Unexplained-weight-loss

Unexpected weight loss can be concerning. This article explores the potential reasons behind losing weight when you're not trying to, and when it might be time to seek medical advice.

Unintentional weight loss of 5%+ body weight within 6 months is a clinically significant symptom warranting GP assessment. Cancer is one of many causes — this article covers the differential diagnosis, which cancer types most commonly cause weight loss, accompanying symptoms that increase concern, and how the NHS clinical pathway works.

Losing weight without trying — particularly 5% or more body weight in 6 months — is a clinical red flag requiring GP assessment. Cancer is one of multiple possible causes. This article covers what weight of loss is medically significant, the full differential diagnosis, when to seek urgent versus routine care, and what investigations to expect.