Restless legs syndrome (RLS) is a common sleep-related movement disorder. Affected individuals feel a strong urge to move the legs during inactivity—like during sleep. Some cases of RLS appear out of nowhere. The strange creeping, tingling, or burning sensations begin developing in your legs for no obvious reason. Doctors aren't sure why, but this disorder often runs in families, so genes may be to blame. Often, though, RLS occurs hand in hand with another health condition, such as kidney disease, diabetes, or pregnancy. Here are seven conditions linked to RLS—and how to cope with them so you can rest easy. 1. Kidney disease Healthy kidneys clear extra water, waste, and toxins from your blood. When they no longer work as well as they should, you have chronic kidney disease. As many as 57% of people with kidney disease also have RLS. Common risk factors for RLS in people with kidney disease include anemia, low iron levels, and high blood calcium levels. Since most people don't have symptoms of kidney disease until the condition is advanced, talk with your doctor about your risk. If you have a kidney transplant, your RLS will usually go away afterward. 2. Parkinson's disease Your body uses a chemical called dopamine to help control your movements. It's a problem with this neurotransmitter that causes both RLS and another movement disorder, Parkinson's disease. In RLS, a shortage of iron—which the brain uses to make dopamine—may be the cause of symptoms. In the brains of people with Parkinson's disease, however, nerve cells that make dopamine are dying. As many as half of people with Parkinson's disease also have RLS. The four primary signs of Parkinson's disease are tremors, stiffness, slow movements, and impaired balance and stability. Tell your doctor if you spot them. As with RLS, there's no cure, but treatment can help control the condition and improve your quality of life. 3. Diabetes In one study comparing people with diabetes to those without, patients with the condition were about three times as likely to have RLS. Another study found RLS in almost half of patients with type 2 diabetes. For people with diabetes, medications to treat neuropathy—the nerve damage caused by high blood sugar—sometimes work better than other treatments for RLS. RLS is also more common in people with pre-diabetes, whose blood glucose levels are higher than normal but not yet high enough to be diagnosed with diabetes. Eating a healthy diet and exercising regularly can help control your blood sugar and prevent diabetes. 4. Rheumatoid arthritis A vicious cycle often forms between RLS and the painful joint condition rheumatoid arthritis. People with rheumatoid arthritis are two to six times more likely to have RLS. When RLS disrupts their sleep, they feel more stress and fatigue, and are more likely to experience debilitating arthritis flare-ups. Pain medications that treat rheumatoid arthritis may deplete iron levels, increasing RLS risk. One study found that only 20% of people with both conditions sought treatment for RLS. But there's good reason to see your doctor: Iron supplements, if needed, and other treatments for RLS can improve many aspects of your health. 5. Pregnancy With the surges of estrogen and other hormones during pregnancy, many women report changes in their sleep patterns. About one-fourth of pregnant women will develop RLS, usually in their last trimester. Besides hormones, changes in levels of the nutrients iron and folate may play a role. RLS usually goes away after your baby is born. But about 60% of women who have RLS during one pregnancy will have it again during the next pregnancy. They're also about four times as likely to develop RLS later in life, when they're not pregnant. Fortunately, the condition hasn't been linked to complications during delivery or to problems with babies' health. 6. Periodic limb movement of sleep About eight in 10 people with RLS also twitch, jerk, or flex their arms or legs during sleep. This separate but related condition is called periodic limb movement of sleep (PLMS). Sometimes you'll wake up because of these movements, but other times, you might not even be aware they're happening. Often, a patient's spouse or partner will be the person most affected by periodic limb movements. To help you—and your loved one—sleep easier, ask your doctor about medications to treat the condition, such as Klonopin or Mirapex. 7. Insomnia If you have RLS, you know that the condition usually worsens at night. Because it interferes with your sleep, RLS contributes to insomnia, or difficulty falling or staying asleep. When insomnia occurs most nights over weeks or months, it's said to be chronic or long-term. With time, loss of sleep can lead to more serious health issues, such as depression, diabetes, and heart disease. Getting treatment for your RLS can improve the quality and quantity of your sleep, easing insomnia. Other medications, counseling, and lifestyle changes like going to bed at the same time every night also can help both conditions.