The common cold and the flu may seem similar at first.

They’re both respiratory illnesses and can cause similar symptoms. But different viruses cause these two conditions. Your symptoms help you tell the difference between them.

Both a cold and the flu share a few common symptoms. People with either illness often experience:

• runny or stuffy nose
• sneezing
• body aches
• general fatigue
• As a rule, flu symptoms are more severe than cold symptoms.

Another distinct difference between the two is how serious they are. Colds rarely cause other health conditions or problems. But the flu can lead to sinus and ear infections, pneumonia, and sepsis.

To determine whether your symptoms are from a cold or from the flu, you need to see your doctor. Your doctor will run tests that can help determine what’s behind your symptoms.

If your doctor diagnoses a cold, you’ll only need to treat your symptoms until the virus has run its course. These treatments can include using over-the-counter (OTC) cold medications, staying hydrated, and getting plenty of rest.

Taking flu medicine early in the virus’ cycle may help reduce severity of illness and shorten the time that you are sick. Rest and hydration are also beneficial for people with the flu. Much like the common cold, the flu just needs time to work its way through your body.

What are the symptoms of the flu?

Here are some of the common symptoms of the flu.

Fever

The flu almost always causes an increase in your body temperature. This is also known as a fever. Most flu-related fevers range from a low-grade fever around 100°F (37.8°C) to as high as 104°F (40°C).

Although alarming, it’s not uncommon for young children to have higher fevers than adults. If you suspect your child has the flu, see your doctor.

You may feel “feverish” when you have an elevated temperature. Symptoms include chills, sweats, or being cold despite your body’s high temperature. Most fevers last for less than one week, usually around three to four days.

Cough

A dry, persistent cough is common with the flu. The cough may worsen, becoming uncomfortable and painful. You may also experience shortness of breath or chest discomfort during this time. Many flu-related coughs can last for about two weeks.

Muscle aches

These flu-related muscle pains are most common in your neck, back, arms, and legs. They can often be severe, making it difficult to move even when trying to perform basic tasks.

Headache

Your first symptom of the flu may be a severe headache. Sometimes eye symptoms, including light and sound sensitivity, go along with your headache.

Fatigue

Feeling tired is a not-so-obvious symptom of the flu. Feeling generally unwell can be a sign of many conditions. These feelings of tiredness and fatigue may come on fast and be difficult to overcome.