Have you been feeling sleepy all day long? This symptom is medically called hypersomnia. It means excessive daytime sleepiness and difficulty staying awake during the day. A foggy head and inability to think straight are common in hypersomnia.

Often, stress and lack of adequate sleep could cause excessive daytime sleepiness. When it is severe, some patients may fall asleep suddenly at any time in any condition – for instance, at work or while they are driving. It is important to know what causes hypersomnia and treat it accordingly.
Symptoms
Hypersomnia could cause the following symptoms:
· Constant tiredness, fatigue, and lack of energy.
· Irritability. Patients with hypersomnia may be easily irritated.
· Inability to remember things or reason smoothly. Many people feel that their heads are in a mess and foggy.

· Snoring. A loud snore during sleep suggests that the patient’s airway is not working properly. For example, for patients with obstructive sleep apnea, the airway narrowing obstructs the normal flow of air into the lung. As a result, the patient still feels very sleepy at the daytime after seemingly adequate sleep.
Causes
For some cases of hypersomnia, a clear underlying cause can be identified. These are often referred to as secondary hypersomnia. However, for a lot of cases, a clear underlying cause cannot be found, and they are called primary hypersomnia or idiopathic hypersomnia.
Primary hypersomnia is very rare. Doctors do not know exactly what causes or triggers primary hypersomnia, but it’s believed that there may be problems in the patients’ brain systems that control sleep and waking functions.

Secondary hypersomnia can be caused by many medical conditions, notably sleep deprivation, alcohol abuse, obstructive sleep apnea, depression, alcohol abuse or certain drugs (e.g., tranquilizers or antihistamines).
Diagnosis
In general, the doctor diagnoses hypersomnia after asking the patient some questions about his/her sleep and daytime sleepiness. Once hypersomnia is diagnosed, the doctor would proceed to investigate the cause for it and thus, blood tests, CT scans and a sleep test called polysomnography may be ordered.

Treatment
For patients with secondary hypersomnia, treating or remedying the underlying cause would be the first-line treatment. For instance, if your doctor determines that your hypersomnia is caused by obstructive sleep apnea, your doctor may recommend continuous positive airway pressure, which is a portable ventilator, to improve your sleep quality and thus decrease daytime sleepiness.
If your doctor determines that you have primary hypersomnia, then you may need to take medications that can boost energy and decrease sleepiness during the day, such as amphetamine and modafinil.

The bottom line
Hypersomnia can be primary or secondary, depending on the specific cause. In order to identify the cause, multiple tests will be needed. Whenever if you suspect that you have hypersomnia, do talk to your doctor. Hope you are tucked in nice and tight.