Self magazine, a popular health and fitness publication for women, ran an article titled "When Weight Gain is a Warning" in their current issue.

If, after you've ruled out the more likely causes -- a hiatus from the gym, a few too many pina coladas, etc. -- the cause of the weight gain remains a mystery, certain health problems may be to blame. The article highlights a few that may be cause for pause.

A 5-POUND GAIN MAY MEAN...

Sleep Apnea. If you're also snoring excessively at night, have been experiencing headaches and feel tired all the time, sleep apnea may be the culprit. How it links to the five pound weight gain is as follows: sleep apnea greatly disrupts sleep, which in turn causes a rise in cortisol levels and the subsequent accumulation of fat. And, if you're not getting much sleep, you're obviously not going to exactly be an animal in the gym (well, maybe a sloth).Polycystic Ovary Syndrome. According to the article, PCOS -- a hormonal disorder that occurs when the ovaries pump out too much testosterone -- is linked to higher-than-usual levels of insulin, resulting in the accumulation and storage of fat.

A 10-POUND WEIGHT GAIN MAY MEAN...

Cushing's Syndrome. Caused by the presence of a benign tumor on the adrenal gland, Cushing's can oftentimes cause acne, muscle weakness, and the development of facial hair in females -- as well as weight gain. This occurs when the benign tumor increases cortisol production, which as explained earlier, increases fat storage.

Metabolic Syndrome. Though not a disease itself, metabolic syndrome is more a collection of risk factors. Nevertheless, as the article asserts, metabolic syndrome can possibly be to blame for sudden and seemingly inexplicable weight gain. Because type 2 diabetes is among the risk factors of which metabolic syndrome is comprised, increased insulin levels often become problematic. As the hormone builds in the blood, it signals to the rest of the body to build up and hoard more fat, consequently leading to weight gain.