If a person loses weight for an unknown reason, it is most likely a disorder in the body.
Unexplained weight loss, or losing weight without trying — particularly if it's significant or persistent — may be a sign of an underlying medical disorder.
If you lose weight for no reason, without effort, be sure to consult a doctor, because this sign may be a symptom of any pathology, disease.
The point at which unexplained weight loss becomes a medical concern is not exact.
Many doctors agree that a medical evaluation is called for if you lose more than 5 percent of your weight in six months to a year, especially if you're an older adult.
Remember, the following factors affect your weight:
- Calorie levels;
- Level of physical activity;
- General state of health;
- Age
- Nutrient absorbtion
- Economic and social factors.
Causes
Unexplained weight loss has many causes, medical and nonmedical. Often, a combination of things results in a general decline in your health and a related weight loss. Sometimes a specific cause isn't found.
Potential causes of unexplained weight loss include:
- Addison's disease (adrenal insufficiency)
- Cancer
- Celiac disease
- Changes in diet or appetite
- Changes in sense of smell
- Changes in sense of taste
- COPD (chronic obstructive pulmonary disease)
- Crohn's disease (a type of inflammatory bowel disease)
- Dementia
- Dental problems
- Depression
- Diabetes
- Heart failure
- HIV/AIDS
- Hypercalcemia
- Hyperthyroidism
- Hypothyroidism
- Medications
- Parkinson's disease
- Peptic ulcer
- Substance abuse (alcohol, cocaine, other)
- Tuberculosis
- Ulcerative colitis
Source:
https://www.mayoclinic.org/symptoms/unexplained-weight-loss/basics/definition/sym-20050700
