Frequently falling sick? It could signal a weakened immune system

Many people brush off frequent illness as stress, weather changes or simply bad luck. A cold that keeps returning, wounds that seem to take forever to heal or a constant feeling of tiredness often become part of daily life. Over time, these experiences feel normal. Yet they may be quiet signals that the body’s immune system is struggling to do its job.

The immune system is the body’s natural defence network. It is made up of white blood cells, antibodies, the lymphatic system, bone marrow and organs such as the spleen. According to the World Health Organisation (WHO), its role is to recognise harmful germs, fight infections and remember past invaders to prevent repeat illness.

A strong immune system responds quickly and effectively, clearing infections with minimal disruption. A weak immune system struggles to mount this response, allowing infections to occur more often, last longer or become more severe. The Centres for Disease Control and Prevention (CDC) notes that repeated or unusually severe infections are among the clearest signs of immune weakness.

Globally, immune vulnerability is reflected in disease patterns. In sub-Saharan Africa, where an estimated 25.6 million people live with HIV, the virus directly damages immune cells, increasing the risk of infections such as tuberculosis and pneumonia. Kenya continues to invest in surveillance and prevention of infectious diseases recognising that weakened immunity can worsen outcomes and strain health systems.

Beyond infectious diseases, studies show that malnutrition remains a major contributor to low immunity across Africa, according to CDC. Deficiencies in iron, zinc and vitamins A and D reduce the body’s ability to produce immune cells and antibodies, particularly among children and women of reproductive age.

Several factors can weaken the immune system. Poor nutrition limits the raw materials the body needs to fight disease. Chronic stress and inadequate sleep interfere with immune signalling, leaving the body less responsive to threats. Long-term illnesses such as diabetes and cancer alter immune function, while medications like steroids and chemotherapy intentionally suppress immunity as part of treatment. Smoking and excessive alcohol use further reduce immune effectiveness.

Health professionals advise seeking medical care if someone experiences frequent infections more than four to six times a year, infections that are unusually severe, unexplained weight loss, night sweats or long-lasting fatigue. These signs suggest the immune system may be under significant strain and needs proper assessment.

Here are common signs of a weak immune system that one should pay attention to and seek timely care to help protect long-term health and strengthen the body’s natural defences:

Frequent infectionsRepeated colds, flu, chest infections or urinary tract infections suggest the immune system is failing to clear germs fully, allowing illness to recur. Slow wound healingWhen cuts or sores take a long time to heal, it may indicate that immune cells are not repairing damaged tissue efficiently. Persistent fatigueFeeling tired all the time, even after enough rest, can be linked to the body constantly fighting infections or struggling to recover. Digestive issuesThe gut contains a large portion of immune cells. Frequent diarrhoea, bloating or stomach upset may reflect immune imbalance. Recurrent skin conditionsSkin infections, fungal rashes or repeated eczema flares occur when the immune system cannot protect the skin barrier effectively. Mouth and gum issuesRegular mouth ulcers, gum infections or sore throats point to reduced local immune defence. Swollen glands or low-grade feversPersistent swelling or mild fever indicates ongoing immune activation without full resolution. Worsening allergies or frequent illness complicationsWhen minor illnesses become severe or lead to complications, or allergies suddenly worsen, it may reflect poor immune regulation.