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Getting sick often: low immunity causes

Adults normally catch two or three colds a year. If you get ill more than that, sleep and stress are the first things to look at.

Common causes

  • 01Adults normally catch 2–3 colds a year
  • 02Short sleep: people sleeping under 6 hours were more likely to catch a cold
  • 03Chronic stress
  • 04Smoking
  • 05Low vitamin D (supplements modestly reduce respiratory infections, most in people who are deficient)

What a doctor may check

Blood sugar and a full blood count if infections are frequent or severe.

When to see a doctor

See a doctor for repeated serious infections (such as pneumonia), infections that keep coming back, persistent fever or unexplained weight loss.

This page is general information, not a diagnosis. Venva's content is written against clinical guidelines and systematic reviews, listed below. See our medical disclaimer.

References

  1. 1.Behaviorally assessed sleep and susceptibility to the common cold. Sleep, 2015.doi:10.5665/sleep.4968
  2. 2.Vitamin D supplementation to prevent acute respiratory tract infections: systematic review and meta-analysis. BMJ, 2017.doi:10.1136/bmj.i6583

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