While contagious viruses are active year-round, fall and winter are when we’re most vulnerable to them. This is due in large part to people spending more time indoors with others when the weather gets cold.

Most respiratory bugs come and go within a few days, with no lasting effects. However, some cause serious health problems. People who use tobacco or who are exposed to secondhand smoke are more prone to respiratory illnesses and more severe complications than nonsmokers.

Colds usually cause stuffy or runny nose and sneezing. Other symptoms include coughing, a scratchy throat, and watery eyes. There is no vaccine against colds, which come on gradually and often spread through contact with infected mucus.

Flu comes on suddenly and lasts longer than colds. Flu symptoms include fever, headache, chills, dry cough, body aches, fatigue, and general misery. Like colds, flu can cause a stuffy or runny nose, sneezing, and watery eyes. Young children may also experience nausea and vomiting with the flu. Flu viruses spread mainly by droplets made when people with flu cough, sneeze or talk. A person might also get flu by touching a surface or object that has flu virus on it.

Flu season in the United States may begin as early as October and can last as late as May, and generally peaks between December and February. According to the Centers for Disease Control and Prevention (CDC):

• More than 200,000 people in the United States are hospitalized from flu-related complications each year, including 20,000 children younger than age 5.
• Between 1976 and 2006, the estimated number of flu-related deaths every year ranged from about 3,000 to about 49,000.
• In the 2013 – 2014 season, there were in the U.S. 35.4 million influenza-associated illnesses, 14.6 medically attended flu illnesses, and 314,000 flu hospitalizations.

• Prevention Tips

Get vaccinated against flu.

With rare exceptions, everyone 6 months of age and older should be vaccinated against flu. Flu vaccination, available as a shot or a nasal spray, can reduce flu illnesses, doctors’ visits, missed work and school, and prevent flu-related hospitalizations and deaths.

It’s ideal to be vaccinated by October, although vaccination into January and beyond can still offer protection. Annual vaccination is needed because flu viruses are constantly changing, flu vaccines may need to be updated, and because a person’s immune protection from the vaccine declines over time. Annual vaccination is especially important for people at high risk for developing serious complications from flu. These people include:

• young children under 5 years, but especially those younger than 2.
• pregnant women
• people with certain chronic health conditions (like asthma, diabetes, or heart and lung disease)
• people age 65 years and older

Vaccination also is especially important for health care workers, and others who live with or care for people at high risk for serious flu-related complications. Since babies under 6 months of age are too young to get a flu vaccine, their mother should get a flu shot during her pregnancy to protect them throughout pregnancy and up to 6 months after birth. Additionally, all of the baby’s caregivers and close contacts should be vaccinated as well.

Wash your hands often. Teach children to do the same. Both colds and flu can be passed through contaminated surfaces, including the hands. FDA says that while soap and water are best for hand hygiene, alcohol-based hand rubs may also be used. However, dirt or blood on hands can render the hand rubs unable to kill bacteria.

Try to limit exposure to infected people. Keep infants away from crowds for the first few months of life.

Practice healthy habits.

• Eat a balanced diet.
• Get enough sleep.
• Exercise.
• Do your best to keep stress in check.

Already Sick?

Usually, colds have to run their course. Gargling with salt water may relieve a sore throat. And a cool-mist humidifier may help relieve stuffy noses.

Here are other steps to consider:

• Call your health care professional. Start the treatment early.
• Limit your exposure to other people. Cover your mouth with a tissue when you cough or sneeze.
• Stay hydrated and rested. Avoid alcohol and caffeinated products which may dehydrate you.
• Talk to your health care professional to find out what will work best for you.

In addition to over-the-counter (OTC) medicines, there are FDA-approved prescription medications for treating flu. Cold and flu complications may include bacterial infections (e.g., bronchitis, sinusitis, ear infections, and pneumonia) that could require antibiotics.

Taking OTC Products

Read medicine labels carefully and follow the directions. People with certain health conditions, such as high blood pressure, should check with a health care professional or pharmacist before taking a new cough and cold medicine.

Choose OTC medicines appropriate for your symptoms. To unclog a stuffy nose, use nasal decongestants. Cough suppressants quiet coughs; expectorants loosen mucus; antihistamines help stop a runny nose and sneezing; and pain relievers can ease fever, headaches, and minor aches.

Check the medicine’s side effects. Medications can cause drowsiness and interact with food, alcohol, dietary supplements, and each other. It’s best to tell your health care professional and pharmacist about every medical product and supplement you are taking.

Check with a health care professional before giving medicine to children.

See a health care professional if you aren’t getting any better. With children, be alert for high fevers and for abnormal behavior such as unusual drowsiness, refusal to eat, crying a lot, holding the ears or stomach, and wheezing.

Signs of trouble for all people can include

• a cough that disrupts sleep
• a fever that won’t respond to treatment
• increased shortness of breath
• face pain caused by a sinus infection
• high fever, chest pain, or a difference in the mucus you’re producing, after feeling better for a short time.

This article appears on FDA’s Consumer Updates page, which features the latest on all FDA-regulated products.