Weight loss: Weight loss is a decrease in body weight resulting from either voluntary (diet, exercise) or involuntary (illness) circumstances. Most instances of weight loss arise due to the loss of body fat, but in cases of extreme or severe weight loss, protein and other substances in the body can also be depleted.

If your weight loss wasn’t due to one of the causes mentioned, and you didn’t lose weight through dieting or exercising, see your GP, as you may have an illness that needs treating.

The following information may give you a better idea of the cause of your weight loss, but don’t use it to diagnose yourself. Always see a GP for a proper diagnosis.