When Women's Fatigue Signals Danger

From Stress to Anemia, What Causes Fatigue And What To Do About It

(CBS)  Adrenal Gland Function
A rare condition in which the adrenal gland, which keeps enough blood and salt circulating in the body, stops functioning can cause people to have low blood pressure and feel exhausted.

Clinical Depression
Significant depression can make a patient extremely tired, craving as much as 16 hours of sleep a day.

Legato warns against what one of her patients calls the "sweat and fret" club, meaning an inclination to lie awake worrying at night.

"if you have a problem that keeps recurring at 3:00 am," she said, "talk to somebody and see if you can't find a solution.

Heart Failure
Heart failure deprives tissues of oxygen, leading to fatigue. This condition can cause someone to feel short of breath from even the smallest activities.

Chronic Fatigue Syndrome
Characterized by an extreme and overwhelming fatigue that doesn't get better with bed rest, it often gets worse with physical or mental activity. Legato says this condition is diagnosed through a process of elimination and sometimes lasts for years. In many cases, the fatigue eventually, mysteriously disappears.