weight loss

Last edited 12/2020 and last reviewed 01/2021

This is a very non-specific symptom. However, an acute weight loss may be indicative of a serious underlying pathology. Below is presented a scheme for thinking about acute weight loss.

Causes of acute weight loss include:

  • insufficient calorie intake:
    • anorexia - associated with infection, malignancy and anorexia nervosa
    • dysphagia e.g. oesophageal carcinoma, oesophageal reflux
    • vomiting e.g. pyloric stenosis, hiatus hernia

  • malabsorptive states:
    • chronic pancreatitis, coeliac disease, Crohn's disease

  • high energy usage:
    • malignancy
    • thyrotoxicosis

Significant unintentional weight loss is defined as (1):

  • unintentional loss of more than 5% of body weight over 6 to 12 months


  • NHS Choices. Unitentional weight loss (Accessed 29/12/2020).