Understanding Upper Respiratory Tract Infections – Causes, Symptoms, and Effective Treatment Strategies

An upper respiratory tract infection, also known as the common cold, is a widespread illness that affects the nose, throat, and sinuses. It is caused by a variety of viruses and can be easily transmitted through coughing, sneezing, and close contact with an infected person. The most common symptoms of this infection include a sore throat, nasal congestion, runny nose, and cough.

When a person becomes infected with a virus, the respiratory tract becomes inflamed and produces excess phlegm. This phlegm can irritate the throat and lead to a persistent cough. In some cases, the infection can also spread to the lower respiratory tract, causing symptoms such as chest congestion and difficulty breathing.

Treatment for an upper respiratory tract infection usually involves managing the symptoms and allowing the body to fight off the infection naturally. Over-the-counter medications, such as decongestants and cough syrup, can help relieve symptoms temporarily. Rest, fluids, and a healthy diet are also important for recovery. In severe cases or if the infection is caused by bacteria, a doctor may prescribe antibiotics.

Prevention is key when it comes to upper respiratory tract infections. Practicing good hygiene, such as washing hands frequently and avoiding close contact with sick individuals, can help reduce the risk of infection. Additionally, getting vaccinated against the flu can also protect against certain strains of the virus that can cause upper respiratory tract infections.

Causes of Upper Respiratory Tract Infection

An upper respiratory tract infection (URI) is a common illness that affects the nose, throat, sinuses, and other parts of the upper respiratory tract. It can be caused by several factors, including:

1. Viral Infections

The majority of upper respiratory tract infections are caused by viruses. Common viruses that cause URIs include the rhinovirus, influenza virus, adenovirus, and coronavirus. These viruses can be easily transmitted through coughing, sneezing, or coming into contact with contaminated surfaces.

2. Bacterial Infections

In some cases, bacteria can also cause upper respiratory tract infections. The most common bacteria associated with URIs are Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis. Bacterial URIs often occur as a secondary infection following a viral infection and may require antibiotic treatment.

3. Allergies

Allergies can also lead to upper respiratory tract infections. When an individual is exposed to allergens such as pollen, dust mites, or animal dander, the body may produce excess mucus, leading to congestion, cough, and a sore throat. This can create an environment where bacteria or viruses can thrive, increasing the risk of infection.

4. Environmental Factors

Various environmental factors can contribute to the development of upper respiratory tract infections. These include exposure to cold air, irritants such as tobacco smoke or chemical fumes, and dry air, which can lead to the drying of the nasal passages and throat, making them more susceptible to infection.

5. Weakened Immune System

Individuals with a weakened immune system are more vulnerable to upper respiratory tract infections. Factors that can weaken the immune system include chronic illnesses, certain medications, stress, lack of sleep, and poor nutrition. When the immune system is compromised, it becomes less effective in fighting off infections.

If you are experiencing symptoms such as cough, phlegm, sore throat, or nasal congestion, it is important to consult a healthcare professional for an accurate diagnosis and appropriate treatment. Treating the underlying cause of the upper respiratory tract infection can help alleviate symptoms and prevent complications.

Symptoms of Upper Respiratory Tract Infection

Upper respiratory tract infection is a common illness that can be caused by various types of viruses or bacteria. It primarily affects the respiratory system, including the nose, throat, and sinuses. The infection can spread easily from one person to another through respiratory droplets.

Cough

A persistent cough is one of the most common symptoms of an upper respiratory tract infection. It can be dry or accompanied by phlegm. Coughing is the body’s natural response to clear the airways from irritants or mucus buildup caused by the infection.

Fever

Fever is another common symptom of an upper respiratory tract infection. It is the body’s way of fighting off the infection and can vary in severity. Mild fevers are generally not a cause for concern, but high fevers should be monitored closely and managed appropriately.

Other symptoms of an upper respiratory tract infection may include:

Sore throat	Achy muscles
Runny or stuffy nose	Fatigue
Sneezing	Headache
Watery eyes	Loss of appetite

If you experience any of these symptoms, it is important to seek medical advice for proper diagnosis and treatment. Upper respiratory tract infections can be managed with rest, fluids, over-the-counter medications, and, in some cases, prescription antibiotics.

Common Symptoms of Upper Respiratory Tract Infection

An upper respiratory tract infection, also known as a cold or the common cold, is a viral infection that affects the nose, throat, sinuses, and larynx. It is a common illness that can affect people of all ages.

The following are common symptoms of an upper respiratory tract infection:

Sore Throat

A sore throat is a common symptom of an upper respiratory tract infection. It can be caused by inflammation of the throat due to the infection. Soreness and discomfort in the throat are often experienced, making it painful to swallow or talk.

Cough

A cough is another common symptom of an upper respiratory tract infection. It can be a dry cough or a cough with phlegm. Coughing helps to clear the airways of excess mucus and irritants. The inflammation caused by the infection can lead to persistent coughing.

Fever

Fever is a common symptom of an upper respiratory tract infection. It is the body’s natural response to the infection and helps to fight off the virus. Fever is often accompanied by other symptoms such as chills, body aches, and fatigue.

Excessive Phlegm

An upper respiratory tract infection often leads to the production of excessive phlegm or mucus. This can cause a runny nose, congestion, and postnasal drip. The phlegm may be clear, yellow, or green in color and is the body’s way of trapping and eliminating the virus.

If you are experiencing these symptoms, it is important to seek medical attention to determine the cause and receive appropriate treatment. Rest, staying hydrated, and over-the-counter medications can help alleviate the symptoms and promote recovery.

Serious Symptoms of Upper Respiratory Tract Infection

While most cases of upper respiratory tract infection are mild and self-limiting, there are certain symptoms that may indicate a more serious condition. It is important to be aware of these symptoms and seek medical attention if they occur.

Fever

A persistent fever is a sign that the infection may have spread beyond the upper respiratory tract. A high body temperature, especially if it persists for more than a few days or is accompanied by other severe symptoms, could indicate a more serious illness.

Severe Illness

If you feel extremely ill or weak, it could be a sign that the infection is affecting your overall health. Severe fatigue, body aches, and difficulty performing daily activities may require medical intervention.

Other serious symptoms may include:

• Chest pain: If you experience chest pain or tightness, it may be a sign of complications such as pneumonia or bronchitis.
• Difficulty breathing: If you are having trouble catching your breath or experiencing shortness of breath, it could be an indication of a more severe respiratory infection.
• Changes in phlegm: If your phlegm becomes discolored (yellow, green, or brown), thicker, or has blood in it, it may be a sign of a more serious infection.
• Prolonged cough: If your cough lasts for more than two weeks and is accompanied by other severe symptoms, it is important to seek medical attention.
• Severe sore throat: If your sore throat becomes extremely painful and is accompanied by difficulty swallowing or breathing, it may be a sign of a more serious infection.

If you experience any of these serious symptoms, it is important to consult a healthcare professional for evaluation and appropriate treatment. Timely intervention can help prevent complications and promote a speedy recovery.

Complications of Upper Respiratory Tract Infection

While most upper respiratory tract infections (URIs) are self-limiting and resolve on their own, there are potential complications that can arise from these infections. These complications can occur when the initial infection is not properly treated or when the individual has a weakened immune system.

Sinusitis:

One of the common complications of an upper respiratory tract infection is sinusitis. This occurs when the infection spreads to the sinuses, leading to inflammation and swelling of the sinus passages. Symptoms may include facial pain, pressure, and congestion. Treatment for sinusitis may involve antibiotics and decongestants.

Otitis Media:

Otitis media, or middle ear infection, can also be a complication of an upper respiratory tract infection. Infection in the throat or nose can travel through the Eustachian tube to the middle ear, causing inflammation and fluid buildup. Symptoms may include earache, hearing loss, and fever. Antibiotics may be prescribed to treat otitis media.

Pneumonia:

In some cases, an upper respiratory tract infection can progress to pneumonia, a more serious infection of the lungs. This can lead to difficulty breathing, chest pain, and cough with phlegm. Pneumonia may require treatment with antibiotics and supportive care to improve symptoms.

Bronchitis:

Bronchitis is another potential complication of an upper respiratory tract infection. It occurs when the infection spreads to the bronchial tubes, causing inflammation and excess mucus production. Symptoms may include a persistent cough with phlegm, shortness of breath, and wheezing. Treatment for bronchitis may involve rest, fluids, and medication to relieve symptoms.

Other complications:

In rare cases, an upper respiratory tract infection can lead to more severe complications such as throat abscesses, pneumonia-related complications like pleural effusion, or infectious mononucleosis. These complications may require specialized treatment and management.

If you experience prolonged or worsening symptoms associated with an upper respiratory tract infection, it is important to seek medical attention to prevent and manage potential complications.

Diagnosis of Upper Respiratory Tract Infection

Diagnosing an upper respiratory tract infection (URTI) involves a thorough examination of the patient’s symptoms and medical history. The most common symptoms of URTI include a cough, fever, and an excessive production of phlegm. These symptoms can help healthcare professionals differentiate between a viral and bacterial infection.

The healthcare provider will typically start by asking the patient about their symptoms, including the duration and severity of the illness. They may also inquire about any recent exposure to respiratory pathogens or any underlying health conditions that could contribute to the infection.

During the physical examination, the healthcare provider will check for signs such as inflamed nasal passages, a red throat, or swollen tonsils. They may also listen to the patient’s lungs to check for any abnormal sounds that could indicate a lower respiratory tract infection.

In some cases, additional diagnostic tests may be ordered. These tests can help confirm the diagnosis of an upper respiratory tract infection and determine the causative agent. Common diagnostic tests for URTI include throat swabs, blood tests, and chest X-rays.

Throat swabs can be used to identify the specific virus or bacteria causing the infection. This information can help guide treatment decisions and prevent the unnecessary use of antibiotics. Blood tests may also be useful in determining the severity of the infection and ruling out other potential causes of the symptoms.

In certain cases, a chest X-ray may be ordered to evaluate the condition of the lungs. This is particularly important if the healthcare provider suspects a lower respiratory tract infection or if the patient’s symptoms are not improving with standard treatment.

Overall, the diagnosis of an upper respiratory tract infection relies on a combination of clinical examination and diagnostic tests. It is important to accurately diagnose the infection to ensure appropriate treatment and prevent the spread of the illness to others.

Tests for Upper Respiratory Tract Infection

When a patient presents with symptoms of fever, cough, phlegm, and respiratory illness, it may indicate an upper respiratory tract infection. To confirm the diagnosis and determine the specific cause of the infection, healthcare providers may order certain tests.

1. Physical Examination

A healthcare provider will first conduct a physical examination to assess the patient’s symptoms. They may listen to the patient’s lungs with a stethoscope to check for any abnormal sounds. They will also examine the throat and nose for signs of inflammation or infection.

2. Throat Swab

A throat swab is a common test used to diagnose upper respiratory tract infections. During this test, a sterile swab is gently rubbed against the back of the throat to collect a sample. This sample is then analyzed in a laboratory to identify the presence of bacteria or viruses that may be causing the infection.

Note: A throat swab may not always be necessary, especially if symptoms are mild and the infection is suspected to be viral rather than bacterial.

In some cases, additional tests may be ordered to further evaluate the patient’s condition. These may include blood tests, chest X-rays, or sputum cultures. It is important to follow the healthcare provider’s recommendations for testing to ensure an accurate diagnosis and appropriate treatment.

Treatment for Upper Respiratory Tract Infection

When it comes to treating an upper respiratory tract infection (URI), the main goal is to relieve symptoms and help the body fight off the infection. The treatment may vary depending on the severity of the infection and the individual’s overall health.

One of the most common symptoms of a URI is coughing, which can be quite bothersome. Over-the-counter cough medicines can help suppress the cough and provide relief. However, it’s important to note that coughing serves a purpose in expelling phlegm and mucus from the lungs, so it’s best to consult with a healthcare professional before taking any medication.

If a sore throat is present, gargling with warm salt water can help alleviate discomfort. Drinking warm fluids such as tea with honey or chicken soup can also provide relief. It’s important to stay hydrated and avoid irritants such as smoking or exposure to secondhand smoke.

Feeling feverish and ill is common with a URI, and over-the-counter pain relievers such as acetaminophen or ibuprofen can help reduce fever and alleviate body aches. It’s important to follow the recommended dosage and consult with a healthcare professional if symptoms worsen or persist.

Resting is crucial when dealing with a URI. Giving the body time to heal and recover helps the immune system fight off the infection. Adequate rest can also help prevent complications and speed up the recovery process.

Additionally, practicing good hygiene can help prevent the spread of the infection. Washing hands frequently, covering the mouth and nose when coughing or sneezing, and avoiding close contact with sick individuals can help reduce the risk of contracting or spreading the infection.

In some cases, a URI may be caused by a viral infection, in which case antibiotics are not effective. However, if the infection is caused by bacteria, a healthcare professional may prescribe antibiotics. It’s important to take the prescribed antibiotics as directed and complete the full course, even if symptoms improve.

It’s worth noting that home remedies and over-the-counter treatments may provide temporary relief, but they are not a substitute for professional medical advice. If symptoms worsen or persist, it’s important to seek medical attention to receive appropriate treatment and prevent potential complications.

Home Remedies for Upper Respiratory Tract Infection

If you are suffering from a sore throat, cough, or nasal congestion, it is possible that you have an upper respiratory tract infection. This type of illness commonly affects the nose, throat, and sinuses.

Symptoms of Upper Respiratory Tract Infection

Some common symptoms of an upper respiratory tract infection include:

• Sore throat
• Cough
• Nasal congestion
• Fever
• Excessive phlegm production

It is important to seek medical advice if you experience prolonged symptoms or if your symptoms worsen over time.

Home Remedies

There are several home remedies that can help alleviate symptoms of an upper respiratory tract infection:

Remedy	How It Helps
Drink warm liquids	Helps soothe a sore throat and keeps the body hydrated
Gargle with saltwater	Relieves a sore throat and reduces inflammation
Use a humidifier	Moistens the air and makes breathing easier
Take over-the-counter pain relievers	Reduces fever, throat pain, and body aches
Get plenty of rest	Allows your body to heal and recover

These home remedies can provide temporary relief and improve your comfort while dealing with an upper respiratory tract infection. However, it is always recommended to consult a healthcare professional for proper diagnosis and treatment.

Prevention of Upper Respiratory Tract Infection

Preventing upper respiratory tract infections (URTI) is essential to reduce the risk of falling ill with illnesses such as the common cold, cough, and flu. These infections affect the upper respiratory tract, including the nose, throat, and sinuses. By following some simple preventive measures, you can reduce your chances of developing an upper respiratory tract infection.

1. Practicing Good Hygiene

One of the most effective ways to prevent upper respiratory tract infections is by practicing good hygiene. This includes washing your hands frequently with soap and water for at least 20 seconds. Avoid touching your face, especially your eyes, nose, and mouth, as this can introduce germs into your system. Additionally, cover your mouth and nose with a tissue or your elbow when coughing or sneezing to limit the spread of infection.

2. Avoiding Close Contact

Another important preventive measure is to avoid close contact with individuals who have respiratory infections. This can help reduce your chances of coming into contact with viruses or bacteria that can cause upper respiratory tract infections. Stay away from crowded places and limit close contact with sick individuals, especially during flu season.

Preventive Measures	Description
Regularly disinfect surfaces	Clean and disinfect frequently touched objects and surfaces, such as doorknobs, cell phones, and keyboards, to reduce the spread of germs.
Stay hydrated	Drink plenty of fluids to keep your respiratory tract moisturized and help prevent infections.
Get enough sleep	Adequate sleep strengthens the immune system, making it less susceptible to infections.
Eat a healthy diet	A balanced diet rich in fruits and vegetables provides essential nutrients that support immune function and overall health.
Exercise regularly	Regular physical activity boosts immune function and helps to prevent respiratory infections.

By incorporating these preventive measures into your daily routine, you can reduce your risk of developing an upper respiratory tract infection. If you do experience symptoms such as cough, phlegm, or fever, it is important to seek medical attention for appropriate diagnosis and treatment.

Coping with Upper Respiratory Tract Infection

Dealing with an upper respiratory tract infection (URI) can be challenging, but there are several steps you can take to cope with this illness.

• Rest: It’s important to rest your body when you have a URI. This allows your immune system to focus on fighting off the infection and helps your body heal.
• Stay hydrated: Drinking plenty of fluids, such as water and warm liquids, can help thin mucus and relieve congestion. It is also important to avoid dehydration, especially if you have a fever.
• Manage symptoms: Over-the-counter medications can help relieve symptoms such as cough, sore throat, and fever. However, it’s important to follow the dosage instructions and consult a healthcare professional if symptoms persist or worsen.
• Use a humidifier: Adding moisture to the air can help alleviate symptoms like nasal congestion and dry throat. Using a humidifier in your room or taking a steamy shower can provide relief.
• Avoid irritants: Irritants such as smoke, dust, and strong odors can further irritate your respiratory tract. It’s best to avoid exposure to these irritants to prevent worsening of symptoms.
• Practice good hygiene: Washing your hands frequently and covering your mouth and nose when you cough or sneeze can help prevent the spread of the infection to others.
• Follow your healthcare professional’s advice: If you have a severe or prolonged URI, it’s important to seek medical advice. Your healthcare professional can provide guidance on appropriate treatment options or further evaluation if needed.

By following these coping strategies, you can help manage your upper respiratory tract infection and speed up your recovery.

When to See a Doctor for Upper Respiratory Tract Infection

If you are experiencing symptoms of an upper respiratory tract infection (URI) such as a cough, sore throat, fever, or excessive phlegm, it is important to know when it is necessary to see a doctor. While many URIs can be managed at home with rest and over-the-counter remedies, there are some situations that warrant medical attention.

If your symptoms are severe, persistent, or worsening, it is recommended to seek medical advice. This is especially true if you have a high fever that does not respond to medication or if you are coughing up blood. These can be signs of a more serious illness or complication.

Additionally, if you have a weakened immune system due to a pre-existing condition or medication, it is important to consult a doctor. URIs can be more severe and harder to treat in these cases.

It is also important to see a doctor if your symptoms are interfering with your daily activities or if they are not improving after a few days. Sometimes, what may seem like a minor illness can develop into something more severe, so it is better to err on the side of caution and seek medical attention.

Overall, if you have any concerns or doubts about your upper respiratory tract infection, it is always better to consult a healthcare professional. They can evaluate your symptoms, provide an accurate diagnosis, and recommend appropriate treatment options to help you recover.

Risk Factors for Upper Respiratory Tract Infection

Upper respiratory tract infections are common ailments that can affect anyone, but certain factors can increase the risk of developing these infections. Understanding these risk factors can help individuals take appropriate precautions to prevent and manage upper respiratory tract infections.

Certain respiratory conditions

Individuals with pre-existing respiratory conditions such as asthma, chronic bronchitis, or chronic obstructive pulmonary disease (COPD) are more susceptible to upper respiratory tract infections. These conditions weaken the immune system and make it harder for the body to fight off infections, increasing the risk of contracting respiratory illnesses.

Close proximity to infected individuals

Upper respiratory tract infections are highly contagious and are usually spread through respiratory droplets from coughing, sneezing, or talking. Being in close proximity to infected individuals, especially in crowded places such as schools, workplaces, or public transportation, increases the risk of coming into contact with the viruses or bacteria that cause these infections.

Weakened immune system

A weakened immune system due to factors such as chronic stress, lack of sleep, poor nutrition, or certain medications can make individuals more susceptible to upper respiratory tract infections. The immune system plays a crucial role in defending the body against pathogens, and when it is compromised, the body’s ability to fight off infections is reduced.

Environmental factors

Exposure to certain environmental factors can increase the risk of developing upper respiratory tract infections. Cold and dry weather conditions can irritate the respiratory tract, making it more susceptible to infections. Additionally, exposure to pollutants, allergens, or secondhand smoke can also weaken the respiratory system and increase the likelihood of developing respiratory illnesses.

Poor hygiene

Practicing good hygiene habits such as frequent handwashing, covering the mouth and nose when coughing or sneezing, and avoiding close contact with individuals who are sick can help reduce the risk of upper respiratory tract infections. Poor hygiene, on the other hand, can increase the likelihood of spreading or contracting respiratory infections.

In conclusion, while upper respiratory tract infections can affect anyone, certain risk factors can increase the likelihood of developing these illnesses. By being aware of these risk factors and taking appropriate preventive measures, individuals can minimize their risk of contracting upper respiratory tract infections.

FAQs about Upper Respiratory Tract Infection

What are the common symptoms of upper respiratory tract infection?

The common symptoms of upper respiratory tract infection include cough, sore throat, runny nose, nasal congestion, sneezing, headache, and fatigue. Some individuals may also experience fever and a general feeling of malaise.

Is phlegm a common symptom of upper respiratory tract infection?

Yes, the production of phlegm is a common symptom of upper respiratory tract infection. The presence of phlegm in the lungs and throat is often accompanied by coughing and can be an indication of an infection in the respiratory tract.

What causes upper respiratory tract infections?

Upper respiratory tract infections are commonly caused by viruses, such as the common cold or influenza. However, bacterial infections can also be a cause. These infections can be spread through close contact with an infected individual or by touching contaminated surfaces.

How can upper respiratory tract infections be treated?

Treatment for upper respiratory tract infections often includes rest, drinking plenty of fluids, and taking over-the-counter medications to relieve symptoms such as fever, congestion, and cough. Antibiotics may be prescribed in cases where a bacterial infection is present. It is important to consult a healthcare professional for an accurate diagnosis and appropriate treatment.

It is worth noting that prevention is also key in reducing the risk of upper respiratory tract infections. This can be achieved by practicing good hygiene, such as washing hands regularly, avoiding close contact with infected individuals, and keeping common areas clean and disinfected.

Myths and Facts about Upper Respiratory Tract Infection

When it comes to upper respiratory tract infections (URIs), there are many myths and misconceptions that can lead to confusion and unnecessary worry. It’s important to separate fact from fiction in order to better understand this common illness. Here, we debunk some of the most common myths surrounding URIs:

• Myth: A sore throat always means you have an upper respiratory tract infection.
  
  Fact: While a sore throat can be a symptom of a URI, it can also be caused by other factors such as allergies or acid reflux. It’s important to consider other symptoms such as fever and cough before jumping to conclusions.
• Myth: A high fever is always present in upper respiratory tract infections.
  
  Fact: Fever can be a symptom of a URI, but not all cases involve an elevated body temperature. Mild or no fever is common, especially in viral infections.
• Myth: Upper respiratory tract infections always involve coughing up phlegm.
  
  Fact: While coughing up phlegm can be a symptom of a URI, it’s not always present. Dry coughs are also common in these types of infections.
• Myth: Antibiotics are the best treatment for upper respiratory tract infections.
  
  Fact: The majority of URIs are caused by viruses, which are not affected by antibiotics. Antibiotics should only be used if there is evidence of a bacterial infection, such as strep throat or sinusitis.
• Myth: Upper respiratory tract infections are not serious and can be ignored.
  
  Fact: While most URIs are mild and resolve on their own, they can cause discomfort and impact daily life. In some cases, complications such as bronchitis or pneumonia can occur, especially in individuals with weakened immune systems.

By understanding the myths and facts surrounding upper respiratory tract infections, you can be better equipped to recognize and manage this common illness. Remember to consult with a healthcare professional if you have concerns or if your symptoms worsen.

Q&A:

What is an upper respiratory tract infection?

An upper respiratory tract infection refers to an infection that affects the nose, sinuses, pharynx, or larynx. It is commonly known as a common cold.

What are the causes of upper respiratory tract infection?

Upper respiratory tract infections are mostly caused by viral infections, such as rhinovirus, coronavirus, and influenza virus. However, bacterial infections, such as Streptococcus pneumoniae, can also cause these infections.

What are the symptoms of an upper respiratory tract infection?

The symptoms of an upper respiratory tract infection include a runny or stuffy nose, sore throat, cough, sneezing, headache, fatigue, and occasionally, a fever.

How can upper respiratory tract infections be treated?

Treatment for upper respiratory tract infections usually involves symptomatic relief, such as rest, fluids, and over-the-counter pain relievers. Antibiotics may be prescribed if a bacterial infection is suspected, but they are not effective against viral infections.

When should I see a doctor for an upper respiratory tract infection?

If your symptoms worsen or do not improve after a few days, or if you develop severe symptoms like high fever, difficulty breathing, or persistent cough, it is advisable to see a doctor for further evaluation and treatment.

What are the common causes of upper respiratory tract infection?

Upper respiratory tract infections are usually caused by viruses, such as the common cold, influenza, or the respiratory syncytial virus (RSV). Bacterial infections can also cause upper respiratory tract infections, but they are less common.

What are the symptoms of upper respiratory tract infection?

The symptoms of upper respiratory tract infection can vary, but commonly include sore throat, coughing, congestion, runny nose, sneezing, headache, and mild body aches. Some people may also experience a fever, fatigue, and loss of appetite.