1. Unexplained weight loss

Losing weight without trying may be a sign of a health problem. An unexplained drop in weight could be caused by many conditions. These include overactive thyroid (hyperthyroidism), diabetes, depression, liver disease, cancer or disorders that interfere with how your body absorbs nutrients (malabsorption disorders).

If you've lost more than 5% of your body weight during the past 6 to 12 months talk to your health care provider.