General
Frequent infections
Catching infections more often than expected, or finding they are more severe, slow to clear or keep coming back, which can simply reflect circumstances but can also signal a problem with blood sugar, the kidneys, the immune system or, rarely, a blood cancer.
Education and reference only. This explains the common causes of frequent infections and the warning signs that need urgent help, in plain language — it is not a diagnosis or a substitute for advice from a clinician. If you feel very unwell or are worried, seek medical help.
Quick answer
What is frequent infections?
Everyone catches infections from time to time, and bouts of coughs, colds and tummy upsets are normal, especially in young children, people in close contact with others and during winter. Frequent infections become a concern when they happen far more often than expected, are unusually severe, take a long time to clear, keep recurring in the same place, or are caused by unusual organisms — these patterns suggest the body's defences may not be working as well as they should.
- Get urgent help: Seek prompt assessment for repeated severe infections, unusual infections, or infections that keep recurring or are slow to clear, as these can mean a problem with the immune system. See a doctor promptly for frequent infections with drenching night sweats, unexplained weight loss, easy bruising or persistent swollen glands, which can point to a blood cancer.
- Self-care: While the cause is being looked into, general measures support your defences.
About frequent infections
Everyone catches infections from time to time, and bouts of coughs, colds and tummy upsets are normal, especially in young children, people in close contact with others and during winter. Frequent infections become a concern when they happen far more often than expected, are unusually severe, take a long time to clear, keep recurring in the same place, or are caused by unusual organisms — these patterns suggest the body's defences may not be working as well as they should. Poorly controlled blood sugar in diabetes weakens the immune response and encourages infections such as skin, urine and fungal infections. Reduced kidney function and some long-term conditions also lower resistance, as can low iron. The immune system itself can be impaired by HIV or, less commonly, by an inherited or acquired immune deficiency. Rarely, repeated or unusual infections together with drenching night sweats, unexplained weight loss or easy bruising can be a sign of a blood cancer, which is why a pattern of frequent, severe or persistent infections deserves investigation rather than being brushed aside.
When to get help
Call 999 or go to A&E if frequent infections comes with any of these warning signs:
- Seek prompt assessment for repeated severe infections, unusual infections, or infections that keep recurring or are slow to clear, as these can mean a problem with the immune system.
- See a doctor promptly for frequent infections with drenching night sweats, unexplained weight loss, easy bruising or persistent swollen glands, which can point to a blood cancer.
- Call 999 or go to A&E for signs of sepsis with any infection — confusion, fast breathing, a high or very low temperature, shivering or rigors, a fast heartbeat or feeling very unwell.
- Seek urgent help if an infection is rapidly worsening, spreading, or not responding as expected, or if you feel much more unwell than the infection seems to warrant.
- See a doctor for recurrent infections with thirst, passing more urine and tiredness, which can point to diabetes.
When to see a doctor
Signs of sepsis — confusion, fast breathing, shivering or rigors, a very high or low temperature, or feeling extremely unwell with any infection — are an emergency; call 999 or go to A&E. Otherwise, book an appointment if you are getting infections far more often than expected, if they are unusually severe, slow to clear or keep coming back, or if they come with night sweats, unexplained weight loss, easy bruising or persistent swollen glands. These patterns deserve investigation to look for an underlying cause such as diabetes, a kidney problem, an immune condition or, rarely, a blood cancer.
Not sure how urgent it is? It is always OK to call NHS 111 for advice, day or night.
What can cause it
Common causes of frequent infections
Frequent infections has many possible causes. Each links to a full, plain-language guide to that condition — what it is, how it's treated and when to seek help.
What helps
Self-care and what you can do
While the cause is being looked into, general measures support your defences. Eat a varied, balanced diet, get enough sleep, stay physically active and manage stress, as all of these help the immune system work well. Wash your hands regularly, look after cuts and skin breaks, and keep recommended vaccinations up to date to reduce preventable infections. If you have diabetes, keeping your blood sugar well controlled markedly reduces infections, so work with your clinician on this. Stop smoking and keep alcohol within sensible limits, as both lower resistance. Importantly, do not ignore a pattern of frequent, severe or persistent infections in the hope it will pass — keep a note of how often they occur, where, and how long they last, and share this with your clinician so the cause can be found.
Answers
Frequent infections: frequently asked questions
How many infections is too many?
There is no exact number, but be concerned if you get infections far more often than those around you, if they are unusually severe, slow to clear or keep recurring, or if unusual organisms are involved. Such a pattern is worth checking with a clinician rather than ignoring.
Can diabetes make me catch infections more often?
Yes. High blood sugar weakens the immune response and encourages recurrent skin, urinary and fungal infections — sometimes these are an early clue to undiagnosed diabetes. Recurrent infections with thirst, passing more urine and tiredness should be checked.
When could frequent infections be a sign of cancer?
Rarely, repeated or unusual infections together with drenching night sweats, unexplained weight loss, easy bruising or persistent swollen glands can point to a blood cancer. This combination of symptoms should prompt a doctor's assessment and blood tests.
What can I do to get fewer infections?
Support your immune system with a balanced diet, enough sleep, regular activity and stress management, wash your hands well, keep vaccinations up to date, and control blood sugar if you have diabetes. But do not ignore a persistent pattern of frequent or severe infections — have it investigated.
Sources
Where this is drawn from
- NICE CKS: Immunodeficiency.
- Blood Cancer UK.
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