Noticeable weight loss is not a concern if you are under stress, and this weight is gained back once you get rid of stress and start feeling happier. However, the unplanned weight loss under conditions when you are not stressed is a concern and maybe the symptom of some underlying disease which needs to be diagnosed. Seeking medical help is the best solution in such circumstances.

The exact cause of unplanned weight loss is not always identifiable. However, some of the common causes of weight loss include depression, cancer, hyperthyroidism (overactive thyroid glands) and excessive treatment of underactive thyroid glands.

The less common causes of unexpected weight loss include:
- Side effects of medicines
- Long-term inflammatory conditions like rheumatoid arthritis
- Dental problems like loss of teeth and mouth ulcers
- Issues of the gut like ulcers
- Diseases causing swallowing problems
- Dementia
- Infection
- Alcohol or drug misuse

Yes. Body weight keeps fluctuating and is not a concern unless the loss is more than 5% of your weight within a period of 6-12 months. Unintentional loss of more than 5% body weight can be a sign of significant malnutrition or some underlying disease.

Diagnosis of unexplained weight loss includes a physical examination. To find the cause, your doctor may ask you:
- The exact weight loss
- Duration in which you lost weight
- Any medicine you are taking currently
- Recent disease
- Recent stress
- Change in exercise pattern
- Increased thirst
- Recent vomiting or diarrhoea
- Amount of alcohol consumption
- Changes in the eating pattern