Your immune system includes organs, lymph nodes, bone marrow, white blood cells, protein, and other hormones. Its job is to ward off bacteria, fungi, parasites, and viruses that can make you sick.
But sometimes your immune system can’t do its job well enough to stop or prevent an illness or infection. If you keep getting sick all the time or notice that you get one infection after another, here’s what you need to know.
Signs of Repeat Infections
Sometimes repeat infections are obvious. For example, if you keep getting urinary tract infections (UTI), you know your body’s struggling to kick the infection. But sometimes repeat infections aren’t as clear.
You might be dealing with them if you’ve had:
- A cold or flu that seems to let up, only to reappear a week to a few weeks later.
- More than one bout of shingles, a painful rash caused by the varicella-zoster virus, which also causes chickenpox. Once you have chickenpox, the virus stays in your body. Shingles can cause rashes in areas of your body where the virus flares up because your immune system isn't as strong.
- Recurrent pneumonia. That's when you’ve had pneumonia -- a serious lower respiratory infection -- and recovered from it, then you get it again a month or more after it cleared.
- Regular fungal or yeast infections. If medication helped you get rid of vaginal yeast infections or fungal infections in your nails or feet, but they reappeared several weeks or months later, your immune system probably isn’t clearing the infection from your system.
Causes of Repeat Infections
Several circumstances or conditions can lead to repeat infections, including:
Lack of sleep. While you sleep, your immune system releases proteins called cytokines, which help fight infection and inflammation. If you get too little sleep, or the shut-eye you do get isn't high-quality, your body will make less infection-fighting cells and antibodies. That makes you more likely to get sick from a virus. It also makes it harder for you to get better once you’re sick.
Smoking. Lighting up suppresses your immune system. It also causes changes to your lungs and airways that make it more likely for you to get sick, and for that sickness to be more serious.
Alcohol misuse. Drinking too much can weaken your defenses. Your immune cells won't work as well and there might be less of them. Even a single binge can temporarily weaken your immune system.
Not washing your hands. Not scrubbing up after you use the bathroom or before you touch your nose and mouth can lead to repeat infections. That’s especially true if you get colds or the flu often. It may seem like you’re getting the same infection, but you might be getting infected with different viruses. That’s why it’s important to wash your hands with soap and water for at least 20 seconds several times a day, especially before you eat or touch your face.
Hereditary factors. Some repeat infections, like pneumonia and bladder infections, may happen because of a genetic predisposition. That's an inherited tendency to get more infections than most people do.
Structural issues. Repeat infections can also happen as a result of how your body is put together. For example, an abnormally shaped urinary tract can leave you more prone to infection.
Antibiotics. Though they often fight infections, using antibiotics regularly to treat yeast infections or other illnesses (like a cold) can make your body more prone to infection. Over time, antibiotics change your body’s microbiome (the group of things like bacteria, fungi, viruses, and genes that live inside your body). Those changes can make it easier for infection to take hold. Antibiotics also make bacteria and other microbes more resistant to them.
Diabetes. It can make things like vaginal yeast infections more likely. That’s because high blood sugar makes it easier for yeast to bind to your vaginal cells. High blood sugar also causes other changes to your body. For example, it slows your blood flow and keeps your nerves from working as well as they can. That can make you more prone to repeat infections, particularly in your feet and other places.
Immune disorders (doctors may call them immunodeficiency disorders) and autoimmune disorders. There are more than 300 immune disorders. Some of the most common include B-cell and T-cell deficiencies. With autoimmune disorders, your body mistakenly attacks its own tissues. This makes it harder for your body to fight infection. Common autoimmune disorders include type 1 diabetes and rheumatoid arthritis.
Multiple myeloma. This is a type of cancer that affects the plasma cells of your bone marrow. Plasma cells make antibodies that help your body fight infection. When you have multiple myeloma, your body makes abnormal plasma cells, which make it difficult for your body to fight infection.
Multiple myeloma is rare and isn’t usually the cause of repeat infections.
If you’ve had more than one infection over the past several months, talk with your doctor to see what might help to clear things up.