The cure for perpetual exhaustion is sometimes as simple as multitasking less and sleeping more. But if you're tired all the time for no obvious reason, there's another possible explanation: anemia.

When people have anemia, their blood doesn't carry enough oxygen to the rest of the body. As a result, they may develop symptoms such as fatigue, weakness, pale skin, headache and dizziness. Although some medical conditions can trigger anemia, the cause is often a lack of adequate iron in the diet.

"Iron-deficiency anemia is increasing in the United States," says Shersten Killip, M.D., an associate professor at the University of Kentucky College of Medicine Department of Family and Community Medicine. Killip thinks eating habits are to blame. Although meat is an excellent source of iron, some grains and vegetables provide valuable amounts too. A person who isn't eating a good variety of these plant foods can be iron-deficient even with a diet that contains red meat, says Killip.

Anemia occurs most often in young women, especially those with heavy menstrual periods. About 12 percent of women younger than 50 have the condition. Because growing bodies need extra iron, children, teens and pregnant women are also prone to anemia. If you suspect that you might be anemic, your doctor can order a simple blood test.

• Choose iron-rich foods. Good options include liver, red meat, poultry, fish and certain plant foods.
• Get enough vitamin B12 and folate. Lack of these vitamins can cause anemia. Vitamin B12 is found in meat, fish, poultry, eggs, milk, other dairy products and some fortified foods. Good natural sources of folate include oranges, legumes, spinach, broccoli and peanuts. In addition, enriched breads, cereals and pasta contain folic acid, a form of folate.
• Skip red wine and tea at meals. They block iron uptake.
• Use cast iron cookware. Some iron will pass into the food.

• Bell peppers
• Broccoli
• Cantaloupe Grapefruit
• Kiwifruit Oranges
• Orange juice
• Potatoes
• Strawberries
• Tomatoes
• Tomato sauce