Flu (Influenza): Complete Guide to Symptoms, Causes, Treatment, Prevention, and When to See a Doctor
Introduction
The flu (influenza) is one of the most common seasonal illnesses affecting children, adults, and seniors every year. While many people recover at home, the flu can become serious—especially for older adults, young children, pregnant women, and individuals with chronic medical conditions. At Passion Health Primary Care, we focus on early diagnosis, proper treatment, and prevention to help patients recover safely and avoid complications.
What Is the Flu?
The flu, medically known as influenza, is a contagious respiratory illness caused by the influenza virus. It primarily affects the nose, throat, and lungs. Unlike the common cold, the flu often begins suddenly and can cause intense symptoms that interfere with daily activities.
Influenza viruses change frequently, which is why people can get the flu more than once and why annual vaccination is recommended.
Types of Influenza Viruses
There are several types of influenza viruses:
- Influenza A – Causes most seasonal flu outbreaks and pandemics
- Influenza B – Common in seasonal flu, especially in children
- Influenza C – Causes mild illness
Seasonal flu vaccines are designed to protect against the most common circulating strains.
Common Flu Symptoms
Flu symptoms often appear suddenly and can range from mild to severe.
Typical Flu Symptoms
- Fever or chills
- Cough
- Sore throat
- Runny or stuffy nose
- Headache
- Muscle aches and body pain
- Fatigue or extreme tiredness
Flu Symptoms in Adults
Adults often experience high fever, severe body aches, headache, and fatigue that can last for several days.
Flu Symptoms in Children
Children may develop additional symptoms such as nausea, vomiting, diarrhea, irritability, and difficulty feeding.
Early flu symptoms may resemble a cold, but worsening intensity is a key difference.
Flu vs Cold: Understanding the Difference
Many patients struggle to tell whether they have the flu or a cold.
Feature | Flu | Common Cold |
Onset | Sudden | Gradual |
Fever | Common | Rare |
Body aches | Severe | Mild |
Fatigue | Extreme | Mild |
Complications | Possible | Rare |
If symptoms are severe or worsening, flu testing at a primary care clinic is recommended.
What Causes the Flu?
The flu is caused by the influenza virus, which spreads easily from person to person through respiratory droplets when someone coughs, sneezes, or talks.
How the Flu Spreads
- Close contact with infected individuals
- Touching contaminated surfaces and then touching the face
- Crowded indoor environments
A person with the flu can be contagious one day before symptoms start and up to seven days after becoming sick.
Flu Risk Factors and High-Risk Groups
Certain people are more likely to develop severe flu illness or complications:
- Adults over age 65
- Children under 5
- Pregnant women
- People with asthma, diabetes, heart disease, or weakened immune systems
High-risk patients should seek medical care early if flu symptoms develop.
Flu Diagnosis and Testing
Flu is often diagnosed based on symptoms and physical examination. In some cases, testing may be recommended.
Flu Tests
- Rapid influenza diagnostic tests
- Molecular (PCR) influenza tests
Testing is especially useful during flu season, in high-risk patients, or when symptoms are severe.
Flu Treatment Options
Antiviral Medications
Prescription antiviral medications, such as oseltamivir (Tamiflu), can shorten illness duration and reduce complications when started within 48 hours of symptom onset.
Supportive Care for Flu
- Rest and hydration
- Fever and pain reducers (acetaminophen or ibuprofen)
- Warm fluids and throat-soothing remedies
⚠️ Aspirin should not be used in children due to the risk of Reye’s syndrome.
Managing Flu Symptoms at Home
Most mild flu cases can be managed at home with proper care:
- Stay hydrated
- Get adequate rest
- Monitor fever and breathing
- Avoid spreading the virus to others
If symptoms worsen or do not improve after several days, medical evaluation is recommended.
Flu Complications
While many people recover fully, the flu can lead to serious complications, including:
- Pneumonia
- Bronchitis
- Sinus and ear infections
- Worsening of chronic medical conditions
Prompt treatment reduces the risk of severe complications.
Flu Prevention
Flu Vaccine (Flu Shot)
The annual flu vaccine is the most effective way to prevent influenza and reduce the severity of illness.
Additional Prevention Tips
- Wash hands frequently
- Avoid close contact with sick individuals
- Cover coughs and sneezes
- Clean frequently touched surfaces
- Stay home when sick
When to See a Doctor for the Flu
Seek medical care immediately if you experience:
- Difficulty breathing or shortness of breath
- Chest pain
- Persistent high fever
- Confusion or severe weakness
- Symptoms that improve and then worsen
At Passion Health Primary Care, we provide timely flu testing, treatment, and preventive care.
Flu Care at Passion Health Primary Care
Our providers offer comprehensive flu care for adults and children, including:
- Same-day flu evaluations
- Rapid flu testing
- Antiviral treatment when appropriate
- Flu vaccinations
- Ongoing support for high-risk patients
We serve patients across multiple Texas locations with compassionate, evidence-based care.
Thoughts
The flu is more than a seasonal inconvenience—it can become serious without proper care. Understanding flu symptoms, causes, treatment options, and prevention strategies helps protect you and your family.
If you or a loved one are experiencing flu symptoms, schedule an appointment with Passion Health Primary Care for expert evaluation and treatment.
