Sleep disorders usually have their roots in a medical problem or a prescription drug taken to treat a disease. The common diseases leading to sleep disorders are cardiovascular, neurological, mental, kidney, and gastroesopheal disorders as well as arthritis.

1. Cardiovascular Disorders

The most common cardiovascular disorders that cause sleep disorders are coronary artery disease and congestive heart failure. Both these disorders can cause obstructive sleep apnea.

Congestive heart failure is characterized by the inability of the heart to pump sufficient blood to satisfy the requirements of the body. As a result of this, blood accumulates in the veins leading to the kidneys, and the resulting edema inflicts a lot of damange to the organs of the body.

Coronary heart disease is characterized by the accumulation of fatty deposits in the arteries that carry blood to the heart, leading to a condition known as atherosclerosis.

2. Endocrine Disorders

Sleep disorders are also the result of endocrine malfunction such as thryroid disorder and diabetes. Diabetes affects the way in which the body stores and uses carbohydrates, proteins, and fats. People who do not manage and control their diabetic condition often suffer from restless leg syndrome.

The hormones released by the thyroid gland regulates the energy levels of the body. A person suffering from hyperthyroidism sweats profusely at night and is unable to enjoy a peaceful night's rest.

3. Neurological Disorders

Neurological disorders such as Alzheimer's disease, strokes, epilepsy, and Parkinson's disease are also responsible for sleep disorders.

Parkinson's disease affects the central nervous system. It's symptoms include difficulties in movement, tremors, unstable posture, slow movements, stiffness in the muscles, and difficulties in walking. Parkinson's disease causes sleep disorders such as sleep onset insomnia and REM sleep behavior disorder.

Alzhiemer's disease impairs the intellectual functions of the brain and causes dementia. It also causes a sleep disorder called fragmentation.

Epilepsy affects the normal electrical functions of the brain and leads to short, sudden changes in it that are recurrent. People suffering from epilepsy are more likely to suffer from insomnia.

Usually, stroke is associated with obstructive sleep apnea.

4. Respiratory Disorders

Those suffering from a respiratory disorder such as chronic obstructive pulmonary disease and asthma usually suffer from an accompanying sleep disorder such as insomnia and sleep fragmentation.

The air passages of those suffering from asthma are inflamed. Chronic obstructive pulmonary disease, also known as COPD, is a group of respiratory disorders that cause untold damage to the lungs and lead to difficulties in breathing.

5. Mental Disorders

People suffering from psychological disorders such as anxiety, bipolar disorder, seasonal affective disorder, depression, and schizophrenia also suffer from sleep disorders such as insomnia and sleep fragmentation.

6. GERD

In gastroesophageal reflux disease, commonly known as GERD, the juices in the stomach flow back into the esophagus, and this leads to sleep fragmentation.

7. Kidney Disorders

In most kidney disorders, the kidneys are unable to filter the waste substances from the blood. They are also unable to maintain a proper balance between salt and water. Such a kidney disorder could lead to insomnia and restless leg syndrome.

8. Arthritis

The intense pain suffered by arthritis patients drives away sleep, resulting in insomnia.

If a sleep disorder is due to a medical condition, the medical condition should be treated first, not the sleep disorder. When the primary cause of a sleep disorder is succesfully treated, it disappears, and the patient finds that he or she can enjoy good sleep.