Getting sick often can come from stress, poor sleep, exposure to germs, or a weakened immune system. See a doctor if it keeps happening.
Common reasons
- Frequent exposure to germs, especially around children.
- Poor sleep and stress.
- Not washing hands.
- Poor diet or low vitamin D.
- Smoking.
- Chronic diseases.
- Immune system problems.
Normal frequency
Adults catch 2 to 3 colds per year, and children 6 to 8.
Boost immunity
Sleep 7 to 9 hours, exercise, eat a balanced diet, get vaccines and wash hands.
See a doctor if
You have repeated serious infections (like pneumonia), long-lasting illness, or weight loss.
Tests
A doctor can check for immune deficiencies, anemia or diabetes.
Why adults get sick often
Adults average 2 to 3 colds a year, and children 6 to 8, according to the CDC and NIH. Many viruses circulate, with more than 200 viruses that cause colds, and immunity to one does not protect against others. Being sick more than that may reflect exposure or other factors.
Common reasons
- Exposure: children, school, daycare, healthcare work, public transport and travel increase contact with viruses.
- Lack of sleep: a study of 164 adults found that those sleeping under 6 hours a night were 4.2 times more likely to catch a cold than those sleeping 7 hours or more.
- Stress: chronic stress raises cortisol and lowers immune response.
- Poor nutrition and deficiency in vitamin D, zinc, iron or protein.
- Smoking and heavy alcohol use.
- Low humidity and cold seasons, when people spend time indoors.
- Not washing hands. Handwashing cuts respiratory illness by about 16%, according to a Cochrane review.
- Chronic diseases such as diabetes, asthma and allergies, which can mimic infections.
- Immune problems, like HIV, cancer treatment, steroid use, or immune deficiency.
Normal frequency
A cold lasts 7 to 10 days, so having 3 in a year means about a month sick. Add flu, COVID-19 and stomach bugs and some people feel sick often. Children in daycare can have 10 or more infections a year.
Boost immunity
- Sleep 7 to 9 hours.
- Exercise moderately, such as 150 minutes per week.
- Eat fruits, vegetables, whole grains and protein.
- Keep vaccines current, including annual flu and COVID-19 boosters.
- Wash hands for 20 seconds, and avoid touching your face.
- Manage stress and limit alcohol.
- Do not smoke.
There is no proven supplement that prevents colds. Vitamin C may slightly shorten colds if taken daily.
See a doctor if
Infections are severe, need more than two antibiotic courses a year, include pneumonia twice, are persistent, or come with weight loss, night sweats or swollen glands. Infections that are unusual or need IV antibiotics suggest an immune problem.
Tests
Doctors may order a blood count, immunoglobulin levels, HIV test, diabetes screening and vaccine response tests.
Immune system facts
Healthy adults catch about 2 to 3 colds per year, and children may have 6 to 8, according to the CDC and NIH. Over 200 different viruses cause colds, with rhinoviruses behind 10 to 40 percent of cases. Sleep under 7 hours doubles the chance of catching a cold in one study compared with 8 hours or more. Chronic stress raises cortisol, which suppresses immune cell activity, and smoking, heavy alcohol use and low vitamin D can add to susceptibility. Exposure to children, crowded transit and poor hand washing raise infection chances. Washing hands for 20 seconds, vaccines for influenza, COVID-19 and others, exercise of 150 minutes per week and a balanced diet lower risk. Frequent serious infections, such as more than 4 ear infections or 2 pneumonias in a year, need an immune evaluation.
Based on data from the CDC and the NIH
