Your Poor Sleep , Could Be Caused , By These Health Problems. According to the American Psychological Association, one-third of adults in the United States sleep less than they should. Sleep experts recommend 7 to 9 hours of sleep per night. Even those who get optimal amounts of sleep may be plagued by daytime fatigue. If you're feeling tired even after a long night of sleep, you might be suffering from one of these conditions. 1: Anxiety. Sufferers of anxiety have increased chances of experiencing a disturbance in their sleep. In many cases, the problem isn't falling asleep, but rather waking up in distress. 2: Arthritis. More than 80% of people with arthritis suffer from fatigue. Lack of sleep can make it difficult for patients to manage pain due to increased levels of stress hormones. 3: Bipolar Disorder. Depression in people diagnosed with bipolar disorder may result in too much sleep. A period of mania might make a bipolar person feel like they don't need much sleep. 4: Diabetes. Sleep deprivation is likely to lead to less insulin and more cortisol. Lack of sleep leads to higher blood sugar levels. Higher levels of sugar in a person's blood can cause issues like insomnia and sleep apnea