Drowsiness - somnolence
Drowsiness is the natural response to the body's need for sleep. Many other factors, such as eating a heavy meal, being bored, or sitting in a warm room, provoke feelings of drowsiness. A person may also experience increased drowsiness during a mild illness, such as a cold or the flu. All of these are natural responses. However, persistent unexplained drowsiness may be associated with a serious illness.
Causes of drowsiness
Alcohol or drug abuse
Even a few alcoholic drinks are enough to make many people feel drowsy. Although people who drink regularly build up a tolerance to alcohol and are able to consume, increasing amounts without falling asleep, even heavy drinkers eventually drift off into a drunken stupor. Heroin and other illicit drugs also can cause drowsiness.
Brain cancer and tumors
Any brain tumor, either cancerous or benign, is serious because it encroaches on vital brain space. As the tumor grows, it crowds normal brain tissue. Besides drowsiness and lethargy, there may be headaches, vomiting, muscle weakness that is often limited to one side of the body, vision problems, a lack of balance and coordination, and personality changes, including irrational behavior and psychosis.
Patients suffering from depression often spend entire days or weeks in bed. They are not necessarily tired, they simply want to sleep all the time. Any marked change in sleep patterns accompanied by other symptoms, such as loss of appetite, feelings of sadness or hopelessness, or disinterest in sex and other activities, indicates possible depression.
Hydrocephaly occurs when the ventricle spaces in the brain are filled with fluid. It is most common in newborn babies, but it may also occur in adults, often in association with a brain tumor or injury. Symptoms include decreased mental function and stupor.
Acute kidney failure is marked by an abrupt drop in urine output, which results in uremia, a buildup in the bloodstream of toxic materials that are normally excreted by the kidneys. This type of kidney failure is a medical emergency requiring dialysis, which entails cleansing the blood with an artificial kidney machine. Symptoms include nausea and vomiting, lethargy and drowsiness, dry skin, convulsions, and twitching.
Many medications can produce drowsiness. Sleeping pills are the most obvious example; others include tranquilizers, antihistamines, and certain heart medications. Heed warnings about driving when taking such drugs.
This sleep disorder may begin with mild symptoms that increase in severity gradually over a period of years. A person who has narcolepsy continually feels drowsy, and the desire to sleep is sometimes irresistible. During an attack of narcolepsy, the person may sleep for only a few seconds to half an hour. These sudden sleep attacks can occur at any time.
People who are markedly overweight may develop a special kind of drowsiness called Pickwickian syndrome (named after the sleepy fat boy in Charles Dickens' The Pickwick Papers). Obese people tend to breathe without moving the diaphragm muscle very much. This type of shallow breathing reduces the amount of air that flows in and out of the lungs, which in turn reduces the amount of carbon dioxide in the body. Low levels of carbon dioxide affect the brain's sleep center, resulting in persistent drowsiness.
Apnea is the periodic cessation of breathing. It occurs most often during sleep, and is most common in overweight men. Often, they are unaware that they stop breathing, but their sleep tends to be fitful and they waken unrested. Many go through the day feeling drowsy and must make a conscious effort to stay awake. Other symptoms include loud snoring and considerable thrashing about in bed.
When the thyroid gland fails to produce adequate thyroid hormone, a condition called hypothyroidism results. This can be due to the failure of either the thyroid or the pituitary gland. In an unborn baby or a growing child, hypothyroidism can lead to serious impairment. In adults, it results in a goiter, or a soft swelling in the neck. Many body processes slow down and the person becomes apathetic and sluggish. Hypothyroidism can be treated by taking replacement thyroid hormone. Screening newborn babies for the congenital form of the disease can detect it early enough to prevent some of its most serious complications.
Advice about drowsiness
- Daytime drowsiness may be due to lack of proper rest at night Giving in by taking a nap may further disrupt normal nighttime sleep. Many elderly people, however, find that they sleep better at night if they nap during the day.
- Exercising can banish drowsiness. People who exercise regularly report that a good workout makes them feel more alert, rather than more tired.