Most of the time, the immune system protects the body from infection. However, some people have a weak immune system that may make them prone to frequent infections.

White blood cells, antibodies, and other components, including organs and lymph nodes, make up the body’s immune system. Many disorders can weaken the immune system and cause a person to become immunocompromised. These immunodeficiency disorders, which range from mild to severe, can be present from birth or may occur as a result of environmental factors. They include:

Sometimes, an immunodeficiency disorder can be so mild that a person may not be aware of it for years. Other times, the disorder is more severe and causes a person to experience frequent infections throughout their life.

In this article, we look at the symptoms of a weak immune system and provide some steps that people can take to improve their chances of staying healthy.

Symptoms of a weak immune system

Woman washing her hands to stay healthy with a weak immune system
A person should practice good hygiene to stay healthy and avoid infections.

The primary symptom of a weak immune system is susceptibility to infection.

A person with a weak immune system is likely to get infections more frequently than most other people, and these illnesses might be more severe or harder to treat.

These individuals may also find themselves dealing with an infection that a person with a stronger immune system would not get.

Infections that people with a weak immune system often get include:

These infections may recur with a high frequency.

The other symptoms of a weak immune system can include the following:

  • autoimmune disorders
  • inflammation of the internal organs
  • blood disorders or abnormalities, such as anemia
  • digestive issues, including loss of appetite, diarrhea, and abdominal cramping
  • growth and developmental delays in infants and children

Tips to stay healthy

People who have a weak immune system can take several steps to maximize their chances of staying healthy and avoiding infections.

Good hygiene

One of the easiest ways for a person with a weak immune system to stay healthy is by practicing good hygiene, which includes washing the hands frequently. The Centers for Disease Control and Prevention (CDC) recommend washing the hands at the following times:

  • before, during, and after preparing meals and snacks
  • before eating
  • after blowing the nose, sneezing, or coughing
  • before and after treating a cut or another open skin wound
  • after having contact with someone who is unwell
  • after using or helping a child use the bathroom
  • after changing a diaper
  • after touching an animal or animal food or waste
  • after touching garbage

Proper handwashing significantly reduces illnesses. According to the CDC, handwashing decreases infectious diarrhea cases by 58 percent in people with a weak immune system.

The CDC also state that hand-washing with soap and water can help protect children and minimize the number of deaths from pneumonia and diarrheal disease in those under the age of 5 years.

Avoid people who are sick

People with weak immune systems should avoid being too near to anyone who has a cold or another infection. Viruses and other infectious illnesses can spread from person to person through close contact. They can also spread in the water droplets that a person expels into the air when they cough or sneeze.

It is not always possible to avoid people who are ill. However, a person with a weak immune system should always avoid close contact, such as hugging or kissing, with the unwell person until the illness resolves. They should also avoid sharing food and beverages with the person.

Disinfect household objects

Germs that have the potential to cause illnesses can live on some surfaces in the home, such as doorknobs and remote controls. A person can reduce the number of germs that inhabit these areas by disinfecting them regularly.

Follow a doctor’s advice on vaccines

doctor speaking to a patient in light filled space
If a person has a weakened immune system, they should follow their doctor’s advice on vaccines.

Doctors generally recommend that most people stay up to date with their vaccinations.

However, they may advise a person with a weakened or compromised immune system to delay or not receive certain shots.

If a short-term illness or a medication is responsible for the weak immune system, the person may be able to have the vaccine once the illness has resolved or they have stopped the treatment.

Examples of vaccines that doctors may recommend delaying or avoiding include:

  • MMR vaccine against measles, mumps, and rubella
  • live flu vaccine
  • MMRV vaccine, which combines the MMR vaccine with a varicella (chickenpox) vaccine
  • rabies vaccine

The CDC recommend a vaccine schedule that most people should try to follow. However, people with a weak immune system should check with a doctor which vaccines are safe for them to have and then follow the doctor’s recommendations. Vaccines can prevent a person from getting seriously ill.

Manage stress

Stress can weaken the immune system further and make a person more susceptible to illness.

Some research shows that a person who is under excessive stress is more likely to get sick.

People with a weak immune system should take steps to manage their stress. Practices that may reduce and manage stress include:

  • yoga
  • meditation
  • massages
  • spending time pursuing hobbies

Get enough sleep

According to the National Sleep Foundation, sleep deprivation has a similar effect on the body’s immune system as stress. Lack of sleep disrupts the normal production of white blood cells, a crucial component of the body’s immune system.

According to the CDC, adults should aim for at least 7 hours of sleep per day, while infants and children need between 8 and 17 hours of sleep depending on their age.

Eat a healthful diet

Woman eating a salad in front of her laptop
A person with a weak immune system should eat a healthful diet.

Eating a healthful, balanced diet can improve a person’s overall well-being.

For people with a weak immune system, doctors generally recommend a diet that is rich in vegetables and fruit, which will provide plenty of nutrients.

If a person is very immunocompromised, for example, because they are undergoing cancer treatment, a doctor may recommend that they take extra steps to avoid foodborne illnesses.

These may include:

  • washing all fruits and vegetables before peeling them
  • avoiding undercooked meats, fish, and eggs
  • refrigerating food promptly
  • choosing pasteurized juices and dairy products over unpasteurized products

Exercise regularly

Regular exercise keeps the body healthy. In addition to strengthening the body, exercise causes the body to release endorphins that reduce stress levels. However, those with weak immune systems should be careful not to push themselves too hard as this can weaken the immune system further.

Therefore, people with a weak immune system may wish to avoid exercising:

  • at too high an intensity
  • too frequently
  • for extended periods without stopping to rest

Consider taking supplements

Some vitamins and minerals affect the immune system. For example, a person who has a vitamin C deficiency can have weakened immunity.

Other vitamins and minerals that can affect immune function include:

It is best to get these nutrients from dietary sources where possible, but if this proves challenging, supplements may help with immunity. A range of supplements, including multivitamins, are available to purchase in health stores or online.


The immune system is a complex system of blood cells and organs, and it protects the body from harmful germs that can cause illness. If a person finds that they are frequently getting infections, they might have a weak immune system.

A person with a weak immune system can take some steps at home to keep themselves healthy and maximize their immune function.