Simply being sick does not mean your illness is contagious. However, it’s best to stay home from work while you have certain symptoms like sneezing, fever, vomiting, chills, or malaise.

Your head’s stuffed up, your throat’s sore, and your body aches like you were run over by a truck. You feel miserable enough to stay home, but you worry that work demands don’t give you the luxury.

Before you pack up your tissues and head into the office, think of your co-workers who’d rather not share your germs.

When deciding whether to stay home, consider your symptoms.

If you have a mild tickle in your throat or a stuffy nose, you should be able to go to work. Allergy symptoms also do not need to keep you from work, since they’re not contagious.

Symptoms that may point to a contagious illness include:

Avoid the office if you have these symptoms or you feel generally miserable. The Centers for Disease Control and Prevention (CDC) also recommends staying home for at least 24 hours after a fever, and other flu-like symptoms (chills, sweating, flushed skin) have cleared up.

Even if you feel all right, your symptoms — or lack thereof — could be deceiving. If you have a mild illness, you can still pass on germs. Contagiousness could last up to 2 weeks, depending on the type of infection.

Each time you sneeze or cough due to a respiratory infection, you release germ-filled droplets into the air. Those bacteria- or virus-filled particles can fly as far away as 6 feet or more — making anyone near you a target.

You also pass on bacteria and viruses when you touch your eyes, nose, or mouth and then touch surfaces with your fingers.

Some germs, including certain influenza (flu) germs, can survive on surfaces such as countertops, doorknobs, and phones for as long as 24 hours to 48 hours. Some cold germs can survive on surfaces for 24 hours. Other viruses, like the flu, for example, can survive on surfaces for as long as two weeks.

Whether germs land on a porous or nonporous surface can determine how long they survive.

Keep in mind that germs may be able to survive on a surface for a number of hours to days, but they may not be capable of causing infection during that entire time.

How long is a cold contagious?

The cold is contagious for a few days before symptoms start and a couple of weeks after exposure to the virus, according to the United Kingdom’s National Health Service (NHS).

How long is the flu contagious?

The flu is typically contagious for 1-4 days before symptoms start and 3 to 7 days after you get sick with symptoms, according to the NHS and the CDC.

How long is a stomach virus contagious?

Norovirus is the most common cause of stomach flu in the United States. It’s typically contagious from the time symptoms start until at least 3 days after you recover, according to various Departments of Heath, including Rhode Island and Washington. In some cases, people can transmit norovirus 2 weeks after they recover.

Rotavirus is common in young children. It’s contagious before symptoms start. It remains contagious for about 1 to 3 weeks, according to the European Centre for Disease Prevention and Control (ECDC)

How to protect others

Your illness might still be contagious when you return to work or school. To protect people around you, take the following steps:

No matter what’s making you sick, try to get plenty of rest and drink lots of fluids. If possible, wait for your symptoms to subside before returning to work.

A doctor may recommend several treatments for your illness. It’s important to consider when these treatments may be helpful and their potential side effects.

Treatments for a cold

Common colds are caused by many different viruses. These viruses spread through the air, just like influenza.

When they make their way into your nose, eyes, or mouth, cold viruses cause symptoms such as:

You might develop a low grade fever, too.

Colds are usually mild, but they can sometimes lead to complications such as bronchitis or pneumonia.

Treat your cold by taking it easy. Drink water and other noncaffeinated fluids and get as much rest as you can.

Cold remedies

You can also take an over-the-counter (OTC) cold remedy. Some of these drugs come in multi-symptom (cold, cough, fever) varieties. Be careful not to treat symptoms you don’t have. You could end up with side effects you don’t expect — or want.

Decongestants

Decongestant nasal sprays help relieve congestion. However, if you use a certain type for more than 3 to 4 days, it could give you rebound rhinitis. Some of these drugs can also cause an increase in blood pressure or a rapid heartbeat.

If you have high blood pressure, an irregular heart rhythm, or heart disease, talk with a doctor before you use a decongestant.

Antihistamines

Antihistamines can also help clear up a stuffy nose, but older ones such as diphenhydramine (Benadryl) can make you sleepy.

Treatments for flu

Influenza viruses can cause respiratory infections.

You’ll have symptoms such as a cough, sore throat, and runny nose. Your body will hurt, you’ll be tired, and you might run a fever over 100°F (37.8°C). People often feel achiness and fatigue before their respiratory symptoms develop.

If you’re at high risk for flu complications because you’re over age 65, you have a chronic health condition, or you’re pregnant, let a doctor know if you get the flu. Also, call a doctor right away if you have any of the more serious flu symptoms, such as trouble breathing or dizziness.

Antibiotics won’t treat the flu since they kill bacteria rather than viruses. Rest, fluids, and OTC pain relievers such as ibuprofen (Advil, Motrin) or acetaminophen (Tylenol) may help you manage your symptoms.

Antiviral drugs (antivirals)

To relieve your symptoms faster, your doctor may prescribe an antiviral drug such as:

For the medication to work, it’s best if you start taking it within 48 hours of your symptoms starting.

Consider taking antiviral drugs even after 48 hours if your doctor recommends them or you’re in regular contact with people who are at high risk, including:

Antiviral drugs can cause side effects such as nausea, vomiting, and diarrhea.

Relenza is an inhaled medication, so do not use it if you have asthma or chronic obstructive pulmonary disease (COPD).

Treatments for a stomach virus

Symptoms of a stomach virus include:

There are no special prescription medications for a stomach virus.

Treatment for norovirus or rotavirus typically involves home remedies such as rest and staying well hydrated with plenty of fluids.

Adults may take OTC medications such as bismuth subsalicylate (Pepto-Bismol) and loperamide (Imodium A-D). Speak with a doctor before giving these medications to children.

Your sneezing, sniffling nose, and watery eyes might not be contagious at all. If they happen at certain times of the year (like spring) and stick around for a few weeks or months, you could have allergies.

Allergies can be triggered by irritants in your environment, such as:

One way to tell the difference between allergies and a contagious infection is that allergies do not typically cause symptoms such as fever and body aches.

Avoiding your triggers is the best way to ward off allergy symptoms.

To relieve allergy symptoms when they occur, try taking one or more of these medications:

  • Antihistamines: Antihistamines block the effects of the chemical histamine. Your immune system releases this chemical when you have an allergic reaction. Some antihistamines can make you tired. They can also cause other side effects, such as constipation and dry mouth.
  • Decongestants: Decongestants narrow blood vessels in your nose to bring down swelling and reduce running. These drugs can make you jittery, keep you awake at night, and increase your blood pressure or heart rate.
  • Nasal steroids: Nasal steroids control inflammation and related swelling in your nose. Some steroid solutions can dry out your nose or cause nosebleeds.

Most respiratory infections clear up within a few days. If you can, stay home until you feel better. This ensures you do not allow your case to get worse — or get anyone else sick.

Also, hold off on returning to work if your treatments are causing side effects such as excessive drowsiness.

If your symptoms do not improve or they start to get worse, let a doctor know. You might have a bacterial infection that needs treatment with an antibiotic.