When is the most infectious period of a cold?

A cold is a common viral infection that affects the upper respiratory tract. It is highly contagious and can spread easily from person to person. Understanding the infectious period of a cold is important for preventing the spread of the virus and protecting those around us.

The infectious period of a cold typically begins a few days before symptoms appear and can last for up to two weeks. During this time, the virus can be easily transmitted through respiratory droplets when an infected person coughs, sneezes, or talks. These droplets can then be inhaled by others or land on surfaces where they can survive for several hours.

It is important to note that the highest concentration of the cold virus is usually found in the early stages of the infection. This means that a person is most contagious during the first few days when symptoms such as a runny nose, congestion, sore throat, and cough start to appear. However, it is still possible to spread the virus even when symptoms are mild or have subsided.

To minimize the risk of spreading a cold, it is important to practice good hygiene measures such as frequent handwashing, avoiding close contact with others, covering the mouth and nose when coughing or sneezing, and cleaning and disinfecting frequently-touched surfaces. By taking these precautions, we can reduce the transmission of the cold virus and protect those who may be more vulnerable to its effects.

Causes of Cold Infections

A common cold is a contagious viral infection that affects the upper respiratory system. It is caused by different types of viruses, including rhinoviruses, coronaviruses, and respiratory syncytial viruses.

The most infectious period of a cold is typically during the first two to three days after symptoms appear. During this time, the virus can be easily spread from person to person through respiratory droplets, such as when an infected person coughs or sneezes.

There are several factors that can increase the risk of contracting a cold, including:

1. Direct Contact

Direct contact with an infected person, such as shaking hands or sharing personal items, can increase the likelihood of acquiring a cold virus. This is especially true during the period when the person is most contagious.

2. Airborne Transmission

Cold viruses can also be transmitted through the air. When an infected person coughs or sneezes, tiny droplets containing the virus can become airborne and potentially infect others who inhale them.

It is important to note that cold viruses can survive on surfaces for several hours, so touching contaminated surfaces and then touching the nose, mouth, or eyes can also lead to infection.

Overall, understanding the causes of cold infections and taking appropriate preventive measures, such as practicing good hand hygiene and avoiding close contact with infected individuals, can help reduce the spread of cold viruses.

Virus	Infectious Period
Rhinovirus	1-3 days
Coronavirus	2-4 days
Respiratory Syncytial Virus	3-5 days

Understanding Common Cold

The common cold is a highly infectious respiratory illness that affects millions of people worldwide every year. It is caused by a variety of different viruses and is especially prevalent during the colder months.

During the infectious period of a cold, individuals can easily spread the virus to others through close contact, such as touching or shaking hands, or through respiratory droplets when coughing or sneezing. These droplets can travel through the air and infect others who are in close proximity.

The infectious period of a cold usually begins a few days before symptoms appear and continues until the symptoms start to improve. This means that a person can unknowingly transmit the virus to others even before they start feeling unwell.

Symptoms of Common Cold

The symptoms of a common cold typically include a runny or stuffy nose, sore throat, cough, sneezing, and mild body aches. Some individuals may also experience a low-grade fever, headaches, and fatigue.

The duration of a cold can vary from person to person, but most people recover within a week or two. However, it is important to note that the infectious period may last longer than the duration of the symptoms, as the body can continue to shed the virus even after the person starts to feel better.

Preventing the Spread of Common Cold

To prevent the spread of the common cold, it is important to practice good hygiene habits. This includes washing hands frequently with soap and water, using hand sanitizers when handwashing is not possible, and avoiding close contact with individuals who have a cold.

Additionally, covering the mouth and nose with a tissue or the elbow when coughing or sneezing can help prevent the spread of respiratory droplets. Disposing of used tissues properly and regularly cleaning frequently-touched surfaces can also help reduce the risk of transmission.

Understanding the infectious period of a cold and taking necessary precautions can greatly reduce the spread of the virus and help protect both individuals and communities from the common cold.

How Does a Cold Spread?

A cold is a viral infection that can be easily spread from person to person. It is caused by a virus that enters the body through the nose or mouth. Once inside the body, the virus attaches to the cells in the respiratory system and begins to reproduce.

The most common way that a cold spreads is through close contact with an infected person. This can occur when an infected person coughs or sneezes, releasing tiny droplets of mucus and saliva into the air. These droplets can then be inhaled by others, allowing the virus to enter their bodies.

Another way that a cold can spread is by touching surfaces or objects that have the virus on them and then touching the nose or mouth. The virus can survive on surfaces for several hours, so it is important to wash your hands regularly to prevent the spread of the virus.

Period of Infectiousness

A person with a cold is most infectious during the first two to three days of their illness. This is when the virus levels in their body are highest, and they are more likely to spread the virus to others. However, it is still possible to spread the virus for up to two weeks after symptoms first appear.

It is important to take precautions to prevent the spread of a cold, such as covering your mouth and nose when coughing or sneezing, washing your hands regularly, and avoiding close contact with others when you are sick. By doing so, you can help reduce the spread of cold viruses and protect yourself and those around you from getting sick.

Symptoms of a Cold

A cold is a common viral infection that affects the nose and throat. It is highly contagious and can easily spread from person to person. The symptoms of a cold may vary, but most people experience similar signs of illness.

Common Symptoms:

Nasal congestion
Runny or stuffy nose
Sneezing
Sore throat
Cough
Mild headache
Fatigue

In some cases, a cold may also cause a low-grade fever, especially in children. It is important to note that these symptoms can overlap with other respiratory illnesses, such as the flu or allergies.

The symptoms of a cold usually develop within one to three days after exposure to the virus. They typically last for about seven to ten days, although some symptoms, such as a cough or nasal congestion, may persist for longer.

Complications:

While a cold is usually a mild illness, it can sometimes lead to complications, especially in individuals with weakened immune systems or underlying health conditions. These complications may include:

Sinusitis
Ear infection
Bronchitis
Pneumonia

If you experience severe symptoms or if they persist for an extended period of time, it is advisable to seek medical attention.

To prevent the spread of a cold, it is important to practice good hygiene, such as regularly washing your hands, covering your mouth and nose when sneezing or coughing, and avoiding close contact with individuals who are sick.

Early Signs of a Cold

When the cold virus enters the body, it starts to replicate and infect the cells in the respiratory system. This initial period is referred to as the early signs of a cold. It is during this period that the virus starts to multiply rapidly, leading to the onset of symptoms.

Typically, the early signs of a cold include a scratchy throat, a runny or stuffy nose, and sneezing. These symptoms may be accompanied by a mild headache and fatigue.

It is important to note that the early signs of a cold can vary from person to person, and some individuals may experience different symptoms or a more severe reaction to the virus. Additionally, the duration of the early signs phase can also vary, lasting anywhere from a few hours to a couple of days.

If you suspect that you are in the early signs phase of a cold, it is crucial to take care of yourself and rest. Drink plenty of fluids, get enough sleep, and avoid contact with others to prevent the spread of the virus.

Remember: The early signs of a cold are the first indication that you have been infected with the virus. It is important to recognize and respond to these symptoms promptly to help alleviate discomfort and reduce the risk of spreading the cold to others.

Common Cold Symptoms

The common cold is a viral infection that affects the upper respiratory system. It is highly contagious and can spread easily from person to person. The cold is most infectious during the first few days of symptoms.

Some common symptoms of a cold include:

Runny or stuffy nose
Sneezing
Sore throat
Cough
Mild headache
Fatigue
Mild body aches
Low-grade fever

These symptoms typically develop within 1-3 days after exposure to the cold virus. The cold is usually at its most infectious stage during this time.

It is important to note that the common cold is different from the flu, although they share some similar symptoms. If you have severe symptoms such as high fever, chest pain, or difficulty breathing, it may be a sign of a more serious condition and you should seek medical attention.

Duration of a Cold

A common cold is a viral infection that primarily affects the nose and throat. It is highly contagious, meaning it can easily spread from person to person. The duration of a cold can vary, but most individuals will experience symptoms for around 7 to 10 days.

Infectious Period

The infectious period of a cold typically begins a day or two before symptoms appear and can last for as long as the symptoms persist. This means that you can spread the cold to others even before you start feeling sick. The virus can be transmitted through respiratory droplets when an infected person coughs or sneezes, or by touching infected surfaces and then touching your eyes, nose, or mouth.

Length of Symptoms

During the course of a cold, the severity of symptoms can vary from person to person. Common symptoms include sneezing, sore throat, runny or stuffy nose, cough, and mild fatigue. These symptoms usually appear within a few days of exposure to the cold virus and gradually improve over the course of a week or so.

It is important to note that colds are caused by different types of viruses, including rhinoviruses, coronaviruses, and respiratory syncytial viruses. Each virus may have slightly different symptoms and duration, but the general range of 7 to 10 days is applicable to most colds.

To prevent the spread of a cold, it is recommended to practice good hygiene, such as washing hands regularly, avoiding close contact with infected individuals, and covering your mouth and nose when coughing or sneezing. Additionally, getting enough rest, staying hydrated, and using over-the-counter symptom relief medications can help alleviate some of the discomfort associated with a cold.

Typical Length of a Cold

The length of a cold can vary depending on various factors, but in general, a typical cold can last anywhere between 7-10 days. During this time, the individual may experience a range of symptoms such as a runny or stuffy nose, cough, sore throat, sneezing, and fatigue.

It is important to note that the infectious period of a cold usually lasts about 2-3 days before symptoms start to appear and can continue for up to a week or more after symptoms have subsided. This means that even after feeling better, a person with a cold can still spread the virus to others.

To reduce the risk of spreading the cold virus, it is recommended to practice good hygiene such as covering your mouth and nose with a tissue or your elbow when coughing or sneezing, washing your hands frequently, and avoiding close contact with others, especially during the infectious period.

Remember: While the duration of a cold can be inconvenient, it is a temporary illness that typically resolves on its own without the need for medical treatment. If symptoms persist or worsen, it is always advisable to consult a healthcare professional.

Factors Affecting Cold Duration

Several factors can influence the duration of a cold. One of the key factors is the period in which the cold is most infectious. During this period, the virus is highly contagious and can easily spread from person to person.

The most infectious period of a cold typically occurs during the first few days after symptoms appear. This is when the virus is most concentrated in the body and is being actively shed from the respiratory system. Coughing, sneezing, and touching contaminated surfaces can all contribute to the spread of the virus during this time.

Another factor that can affect the duration of a cold is the individual’s immune response. A strong immune system can help fight off the virus more effectively, leading to a shorter duration of symptoms. On the other hand, a weakened immune system may prolong the cold and make the symptoms more severe.

Additionally, certain lifestyle factors can impact the length of a cold. Adequate rest, hydration, and a healthy diet can all support the immune system and shorten the duration of symptoms. Conversely, stress, lack of sleep, and poor nutrition can weaken the immune system and prolong the cold.

It is worth noting that individual variation plays a role in how long a cold lasts. Some people may recover from a cold within a few days, while others may experience symptoms for a week or longer. This can depend on various factors such as overall health, age, and the specific strain of the virus causing the cold.

In conclusion, the duration of a cold can be influenced by several factors including the infectious period, immune response, lifestyle choices, and individual variation. Taking steps to support the immune system and adopting healthy habits can help reduce the duration of a cold and alleviate symptoms.

Infectious Period of a Cold

When it comes to the common cold, one of the most important factors to consider is its infectious period. The infectious period of a cold refers to the time during which a person is most likely to spread the virus to others.

Typically, the infectious period of a cold starts from a few days before symptoms appear and can last for up to a week or even longer. This means that a person can be contagious and spread the virus to others even before they start showing any signs of illness.

How is a Cold Spread?

The common cold is primarily spread through respiratory droplets that are released when an infected person coughs, sneezes, or talks. These droplets can then be inhaled by another person, leading to infection. It can also be spread by touching surfaces or objects that have the virus on them and then touching the nose, mouth, or eyes.

It’s important to note that the virus can also be spread by people who have a cold but are asymptomatic, meaning they do not show any symptoms. This makes it even more crucial to practice good hygiene and follow preventive measures, such as washing hands regularly, covering the mouth and nose when coughing or sneezing, and avoiding close contact with people who are sick.

Preventing the Spread of a Cold

To prevent the spread of a cold, it is important to take certain precautions. These include:

Hand hygiene: Wash your hands frequently with soap and water for at least 20 seconds. If soap and water are not available, use an alcohol-based hand sanitizer.
Cover your mouth and nose: Use a tissue or your elbow to cover your mouth and nose when coughing or sneezing. Dispose of tissues properly and wash your hands afterward.
Avoid close contact: Try to maintain a distance of at least 6 feet from people who are sick, especially if they are coughing or sneezing.
Clean and disinfect surfaces: Regularly clean and disinfect frequently-touched surfaces and objects, such as doorknobs, light switches, and cell phones.

By following these preventive measures and being aware of the infectious period of a cold, you can greatly reduce the risk of spreading the virus to others and help protect the health of yourself and those around you.

When Does a Cold Become Infectious?

One of the most common questions about colds is when the virus becomes infectious. Understanding the infectious period of a cold can help prevent the spread of the virus and protect those around you.

Typically, a person with a cold becomes infectious a few days before symptoms appear. This means that you can spread the virus to others even if you don’t feel sick yet. The infectious period of a cold usually starts from one or two days before symptoms begin and lasts for about a week.

During this infectious period, the cold virus can be easily transmitted through respiratory droplets when an infected person coughs or sneezes. These droplets can then be inhaled by others, making them susceptible to catching the cold. Additionally, the virus can also be contracted by touching contaminated surfaces and then touching your nose or mouth.

It’s important to note that everyone’s immune system is different, and some people may be more susceptible to catching a cold than others. Certain factors, such as age, underlying health conditions, and weakened immune systems, can increase the risk of contracting the virus.

To prevent the spread of a cold, it is essential to practice good hygiene. This includes frequently washing your hands, especially after coughing, sneezing, or touching potentially contaminated surfaces. Using hand sanitizers can also be effective in killing the cold virus. Additionally, covering your mouth and nose with a tissue or your elbow when coughing or sneezing can help prevent the spread of respiratory droplets.

Key Points about the Infectious Period of a Cold:
• Infectious period: Usually starts 1-2 days before symptoms and lasts approximately one week.
• Transmission: Through respiratory droplets and touching contaminated surfaces.
• Prevention: Good hygiene practices, such as frequent handwashing and covering mouth and nose when coughing or sneezing.
• Risk factors: Age, underlying health conditions, and weakened immune systems can increase the risk of catching a cold.

Conclusion

Understanding the infectious period of a cold is crucial for preventing its spread. By being aware of when a cold becomes infectious, and practicing good hygiene measures, we can minimize the risk of transmitting the virus to others and protect our communities.

How Long is a Cold Infectious?

A common cold is a viral infection that affects the nose and throat. It is highly contagious and can be easily spread from person to person. The length of time that a cold is infectious can vary, but generally, it is most contagious during the first few days of the illness.

The period of highest infectiousness typically starts one to two days before symptoms appear and continues until the symptoms start to improve. This means that you can spread the cold virus to others even before you know you are sick. It is important to take precautions and practice good hygiene to prevent the spread of the virus.

During the infectious period of a cold, the virus can be spread through respiratory droplets when an infected person coughs, sneezes, or talks. These droplets can be inhaled by others or land on surfaces, where they can survive for several hours. Touching these surfaces and then touching your face, particularly your nose or mouth, can result in contracting the virus.

To reduce the risk of spreading a cold, it is important to cover your mouth and nose when coughing or sneezing, wash your hands frequently with soap and water, and avoid close contact with others, especially if they are showing symptoms of a cold.

In conclusion, the infectious period of a cold can last for several days, with the highest risk of spreading the virus occurring in the early stages of the illness. Taking appropriate precautions and practicing good hygiene can help prevent the transmission of the cold virus to others.

Prevention and Treatment

To prevent the spread of the common cold, it is important to practice good hygiene. This includes washing your hands frequently with soap and water, especially after coming into contact with someone who has a cold. It is also advisable to avoid close contact with individuals who are infected with the cold virus, as the virus can be easily transmitted through respiratory droplets when an infected person coughs or sneezes.

In addition to practicing good hygiene, there are a few other measures you can take to reduce your risk of catching a cold. These include:

Getting vaccinated: Some colds are caused by certain strains of the influenza virus, so getting an annual flu vaccine can help protect against these strains.
Boosting your immune system: Eating a healthy diet, getting regular exercise, and getting enough sleep can help strengthen your immune system, making you less susceptible to cold viruses.
Avoiding touching your face: Cold viruses can enter your body through your nose, eyes, or mouth, so avoiding touching your face with unwashed hands can help reduce the risk of infection.
Using tissues or your elbow to cover your mouth and nose: When coughing or sneezing, using a tissue or your elbow to cover your mouth and nose can help prevent respiratory droplets from spreading the virus.

If you do catch a cold, there are several measures you can take to alleviate the symptoms and speed up recovery. These include:

Rest: Getting plenty of rest allows your body to focus on fighting off the cold virus.
Stay hydrated: Drinking plenty of fluids can help thin mucus and relieve congestion.
Over-the-counter remedies: Over-the-counter cold medications can help alleviate symptoms such as a runny nose, sore throat, and cough.
Warm baths and steam: Taking a warm bath or inhaling steam from a bowl of hot water can help relieve nasal congestion and ease breathing.
Gargling saltwater: Gargling warm saltwater can help soothe a sore throat.

It is important to note that antibiotics are not effective against cold viruses, as they only work against bacteria. Therefore, they should not be used for the treatment of a cold unless otherwise prescribed by a healthcare professional.

Tips for Preventing Colds

During the most infectious period of a cold, it is important to take preventive measures to avoid catching the virus. Here are some tips to help you stay healthy:

1. Practice Good Hygiene

Wash your hands frequently with soap and water for at least 20 seconds. Avoid touching your face, especially your eyes, nose, and mouth. Cover your mouth and nose with a tissue or your elbow when coughing or sneezing.

2. Boost Your Immune System

Eat a well-balanced diet rich in fruits, vegetables, and whole grains. Get enough sleep and exercise regularly to strengthen your immune system. Consider taking vitamin supplements, such as vitamin C and zinc, to support your immune health.

3. Stay Hydrated

Drink plenty of fluids, such as water, herbal tea, and clear broths, to keep your respiratory system hydrated and help flush out toxins from your body.

4. Avoid Close Contact

Avoid close contact with individuals who have a cold, especially during their most infectious period. If you do interact with someone who is sick, maintain a distance of at least six feet and wear a mask.

5. Keep Your Environment Clean

Clean and disinfect frequently-touched surfaces, such as doorknobs, light switches, and electronic devices. Use products that are effective against viruses to reduce the risk of contamination.

6. Stay Active Outdoors

Spending time outdoors and getting fresh air can help reduce the spread of cold viruses. Practice social distancing and avoid crowded places.

By following these tips, you can minimize your risk of catching a cold during its most infectious period.

Period	Infectious
Most infectious period of a cold	Yes

Treatment Options for Colds

When it comes to treating a cold, it is important to understand the infectious period. This is the time when the virus is most easily spread from person to person. During this period, it is crucial to take precautions to prevent the spread of the virus.

There are several treatment options available for colds. One option is to use over-the-counter medications to alleviate the symptoms. These medications can help to reduce fever, relieve congestion, and ease coughing. It is important to read the labels carefully and follow the recommended dosage instructions.

Another treatment option is to drink plenty of fluids. Staying hydrated can help to thin mucus and relieve congestion. Warm liquids, such as herbal teas or chicken soup, can also provide comfort and soothe a sore throat.

Resting is also important during the infectious period of a cold. The body needs time to recover and fighting off the virus takes a lot of energy. Make sure to get plenty of sleep and avoid overexertion.

In addition to these treatments, it is important to practice good hygiene. Wash your hands frequently with soap and water to prevent the spread of the virus. Avoid close contact with others, especially during the contagious period. Cover your nose and mouth when sneezing or coughing to prevent the spread of droplets.

If symptoms persist or worsen after several days, it may be necessary to seek medical attention. A healthcare professional can provide further guidance and recommend appropriate treatment options.

In summary, the treatment options for colds include over-the-counter medications, staying hydrated, resting, practicing good hygiene, and seeking medical attention if necessary. By taking these steps, you can help to alleviate symptoms and prevent the spread of the virus during the infectious period.

When to Seek Medical Attention

If you are experiencing cold symptoms, it is important to know when to seek medical attention. While the common cold is generally a mild illness that resolves on its own, there are certain situations where medical intervention may be necessary.

1. Prolonged or severe symptoms

If your cold symptoms persist for more than 10 days or if they are particularly severe, it may be a sign of a more serious infection. Seek medical attention if you experience high fever, severe headache, persistent cough, or difficulty breathing.

2. Symptoms in vulnerable populations

In some individuals, such as young children, the elderly, or those with weakened immune systems, a cold can lead to complications. If you or a loved one falls into one of these vulnerable populations and experiences cold symptoms, it is important to consult a healthcare professional for advice.

Children: If your child is under 3 months old and has a fever, cough, or difficulty feeding, seek medical attention immediately. For children between 3 months and 2 years old, consult a healthcare professional if their symptoms worsen or do not improve after a few days.
Elderly: Older adults are more susceptible to complications from colds. If you are over the age of 65 and experience severe symptoms or if your symptoms do not improve after a week, contact your healthcare provider.
Immunocompromised individuals: People with weakened immune systems, such as those with HIV/AIDS or undergoing chemotherapy, should seek medical attention if they develop cold symptoms.

Remember to follow the guidance of healthcare professionals and seek medical attention when necessary. They will be able to provide proper diagnosis and recommend appropriate treatment to ensure your well-being.

Complications of a Cold

A cold is a common viral infection that affects the nose and throat. While most colds are mild and resolve on their own within a week, some individuals may experience complications during or after the course of the illness.

Possible complications

In certain cases, a cold can lead to secondary infections such as sinusitis, bronchitis, or pneumonia. Sinusitis occurs when the nasal passages become inflamed, leading to facial pain, pressure, and congestion. Bronchitis refers to inflammation of the bronchial tubes, causing a persistent cough and difficulty breathing. Pneumonia is a more serious infection that affects the lungs, causing symptoms such as chest pain, high fever, and coughing up phlegm.

Additionally, individuals with weakened immune systems, such as those with chronic diseases or compromised immune function, may be at a higher risk of developing complications from a cold. These individuals may experience more severe symptoms and may be more susceptible to developing secondary infections.

Preventing complications

To reduce the risk of developing complications from a cold, it is important to practice good hygiene, such as washing hands frequently, avoiding close contact with individuals who are sick, and covering the mouth and nose when coughing or sneezing. It is also essential to stay hydrated, get plenty of rest, and eat a healthy diet to support the immune system.

If you or a loved one experience severe or prolonged symptoms associated with a cold, it is advisable to seek medical attention. A healthcare professional can provide appropriate treatment and determine if further evaluation or management is necessary to prevent or address any potential complications.

Remember, while a cold is generally a mild illness, it is important to take appropriate measures to prevent complications and ensure a speedy recovery.

When Should I See a Doctor?

If you suspect that you have a cold and are concerned about your symptoms, it is important to consult with a doctor. While the common cold is a viral infection that typically goes away on its own within a week or two, there are certain situations where medical attention may be necessary.

Severe Symptoms

If your cold symptoms are severe and you are experiencing high fever, persistent cough, difficulty breathing, or chest pain, it is important to see a doctor as soon as possible. These symptoms could be signs of a more serious respiratory infection or complication.

Worsening Symptoms

If your cold symptoms are getting worse instead of improving after a week, it is advisable to seek medical advice. Your doctor may want to evaluate your condition and rule out any underlying infections or other health issues.

Special Cases

There are certain groups of people who should be especially cautious and seek medical attention if they have a cold. These include:

Pregnant women
Elderly individuals
Individuals with a weakened immune system
Individuals with chronic health conditions

These individuals may be at a higher risk of complications from the common cold, and it is important for them to receive appropriate medical care.

In conclusion, while the common cold is generally a mild and self-limited illness, it is important to see a doctor if you have severe symptoms, worsening symptoms, or if you are in a high-risk group. Seeking medical attention can help ensure accurate diagnosis and appropriate treatment.

Question and answer:

How long is a person with a cold infectious?

A person with a cold can be infectious starting from one to two days before symptoms appear and up to a week after.

Can a person still be infectious with a cold even if they feel better?

Yes, even if a person feels better, they can still be infectious for up to a week after symptoms began.

Can you catch a cold from someone who is not showing symptoms?

Yes, it is possible to catch a cold from someone who is not showing any symptoms. This is because the virus can be present in their body even if they are not actively showing signs of being sick.

How long does it take for a cold to develop after being exposed to the virus?

It can take one to three days for a person to develop symptoms after being exposed to the cold virus.

When is the peak infectious period for a cold?

The peak infectious period for a cold is usually during the first two to three days after symptoms appear.

What is the most infectious period of a cold?

The most infectious period of a cold is in the first two to four days after symptoms start.