Mono (Mononucleosis)

Mono is a viral infection, usually caused by the Epstein Barr virus. Mono symptoms include extreme tiredness, a severe sore throat, fever, and swollen glands in the neck. Most people recover in 2 to 4 weeks, but tiredness can last longer.

What Is It

Mono spreads through saliva, which is why it is called the kissing disease. It also spreads through shared drinks, utensils, and lip balm. It is most common in teens and young adults. Symptoms start 4 to 6 weeks after exposure. Mono can swell the spleen, which can tear with hard contact.

Symptoms

Extreme tiredness
A severe sore throat
Fever
Swollen glands in the neck and armpits
Swollen tonsils, sometimes with white patches
Headache, body aches, and poor appetite

Not sure it’s mono? Strep throat also causes a sore throat, fever, and swollen glands, but the tiredness is not as deep. Some people have strep and mono at the same time, so testing for both helps.

Treatment

At your visit: Rapid tests can check for mono and strep. Mono is a virus, so antibiotics do not help, and some can cause a rash. Treatment focuses on the sore throat and fever. The spleen is checked before returning to sports.

At home:

Rest as much as your body needs
Drink plenty of fluids and use throat lozenges or warm salt water gargles
Use over the counter pain relievers as directed
Avoid contact sports and heavy lifting for at least 4 weeks

Most people feel better in 2 to 4 weeks. Tiredness can last a few months.

When to Get Care for Mono

Watch at Home

Mild tiredness and sore throat, slowly improving
Able to eat and drink
Mono already diagnosed and getting better

Come to Urgent Care Today

A severe sore throat with fever and swollen glands
Tiredness that keeps you from school or work
A sore throat lasting more than a week
Trouble swallowing food
A rash after starting an antibiotic

Go to the Emergency Department

Sudden, sharp pain in the upper left belly or left shoulder
Trouble breathing or noisy breathing
Drooling or unable to swallow liquids
Fainting or feeling very lightheaded

FAQ

What are the first signs of mono?

The first signs of mono are usually deep tiredness, a sore throat, and fever. Swollen neck glands and swollen tonsils often follow over the next few days.

Is mono contagious?

Mono is contagious through saliva, from kissing, sharing drinks, or sharing utensils. The virus can spread for weeks to months, so avoid sharing cups and utensils.

How long does mono last?

Mono usually lasts 2 to 4 weeks. Tiredness can linger for a few months, so return to full activity slowly.

When can I play sports after mono?

You can usually return to contact sports at least 4 weeks after mono starts, once you feel well and a provider clears you. A swollen spleen can tear with a hit.

Can urgent care test for mono?

Yes, urgent care can test for mono with a rapid test. Vitality Urgent Care offers rapid mono and strep testing. No appointment or referral is needed.

Can adults get mono?

Yes, adults can get mono, though most adults had it as children or teens without knowing. Adults often have more tiredness and less sore throat.

Last reviewed October 2026