How much weight loss is a concern?
Your body weight can regularly fluctuate, but the persistent, unintentional loss of more than 5% of your weight over 6 to 12 months is usually a cause for concern. Losing this much weight can be a sign of malnutrition, where a person's diet doesn't contain the right amount of nutrients.
You should pay particular attention if you experience other symptoms, such as:
- tiredness
- loss of appetite
- a change in your toilet habits
- an increase in illnesses or infections
Other common causes of unexpected weight loss
Unintentional weight loss does not always have an identifiable underlying cause but, in addition to the causes already mentioned, it's often the result of:
- depression
- an overactive thyroid gland (hyperthyroidism), or over-treating an underactive thyroid
- cancer
Less common causes of unexpected weight loss
Less frequently, unexpected weight loss may be the result of:
- the side effects of certain medications
- alcohol misuse or drug misuse
- heart, kidney, lung or liver disease
- a problem with the glands that secrete hormones – such as Addison's disease or undiagnosed diabetes
- a long-term inflammatory condition, such as rheumatoid arthritis or lupus
- dental problems – such as losing teeth, having new orthodontics, or mouth ulcers
- a condition that causes dysphagia (swallowing problems)
- a problem with the gut, such as a stomach ulcer, Crohn's disease, ulcerative colitis or coeliac disease
- a bacterial, viral or parasitic infection, such as persistent gastroenteritis, tuberculosis (TB) or HIV and AIDS
- dementia – people with dementia may be unable to communicate their eating needs
