Several medical conditions can trigger unexpected weight loss, sometimes before other symptoms become obvious.
One common cause is hyperthyroidism, a condition in which the thyroid gland becomes overactive.
Dr Bagwala explained, “One of the common causes is an overactive thyroid gland or hyperthyroidism, which increases the body’s metabolism and causes the body to burn calories more quickly.”
Another major contributor is diabetes.
“Another possible side effect of diabetes is weight loss, especially if blood sugar is not controlled. In such cases the body can’t utilize glucose effectively for energy and starts to convert fat and muscle into food products,” he said.
Digestive disorders can also play a role. Conditions that interfere with the body’s ability to absorb nutrients may leave a person eating normally but still losing weight.
Chronic infections, inflammatory diseases, and certain long-term illnesses can create a similar effect. In many cases, weight loss becomes one of the earliest visible clues that something deeper is happening inside the body.
The US National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) notes that unexplained weight loss can be a symptom of several digestive disorders that affect nutrient absorption and overall health.