Weakened immune system, immune deficiency or immunodeficiency

The disruption of the immune system can lead to immune deficiency.


The disruption of the immune system can lead to immune deficiency. This increases susceptibility to bacterial, viral, fungal and other parasitic infections. Good hygiene practices can prevent such infections.


Main symptoms

  • Trivial infections such as frequently recurring colds
  • Infections caused by pathogens that would not make a healthy person ill
  • Unexpectedly severe infections

Other symptoms

  • General feeling of being unwell
  • Exhaustion and fatigue

Causes and treatment


  • Radiation therapy, chemotherapy
  • Cortisone or other immunosuppressive medications
  • Certain infectious diseases (e.g. AIDS)
  • Cancer (in particular some forms of leukaemia)
  • Diabetes mellitus (diabetes)
  • Major surgery
  • Removal of the spleen
  • Prolonged stress
  • Nicotine, alcohol or drug abuse
  • Unbalanced diet, incorrect and poor nutrition
  • Advancing age

Further treatment by your doctor / in hospital

Possible tests
  • Blood test (number of immune cells, search for infections)
  • Chest x-ray
  • CT scan (computed tomography)
Possible therapies
  • Depending on the underlying cause

What can I do myself?

  • Practice hygiene measures such as hand washing or disinfection
  • Avoid contact with people suffering a cold
  • Maybe wear a face mask
  • Avoid mass gatherings and public transport
  • A healthy lifestyle strengthens the immune system (nutrition, exercise, no smoking, etc.)

When to see a doctor?

  • Frequently recurring colds or other infectious diseases (in particular if they last considerably longer than a week)
  • Occurrence of unusual symptoms during a cold, such as severe headaches or dizziness
  • Repeated occurrence of bacterial infections (e.g. pneumonia)
  • Repeated occurrence of abscesses (collections of pus)


Weakened immune system, immune deficiency, immunodeficiency

Exclusion of liability

CSS offers no guarantee for the accuracy and completeness of the information. The information published is no substitute for professional advice from a doctor or pharmacist.