Why Do you Feel Sleepy Despite Getting Enough Sleep?

A sleepy haze after a late night, a stressful week or a large meal can happen from time to time and the blaze will fade when you get the sleep you need. Persistent sleepiness is a different thing. There are two complaints doctors split: 

• Sleepinessis an inclination towards sleep, especially during meetings, on the way to work or when reading. 
• Fatigueis when you feel low on energy or motivation and are still unable to get to sleep. 

Sleepiness indicates sleep disturbance, fatigue with no sleepiness indicates anaemia, thyroid condition, depression or chronic illness. Plus, hours in bed do not necessarily equal hours of sleep: If you spend eight hours sleeping but wake up during the night to breathe, move your legs, listen to music, or drink a glass of wine, the duration of sleep may not be as restful as you think.

This timeline is a general guide. Individual patterns depend on the underlying cause.

• Obstructive sleep apnea:airway blocks regularly during sleep, leading to short periods of wakefulness that you may not remember. Symptoms are noisy snoring, gasping, headaches in the morning and high blood pressure. It's confirmed by a sleep study. 
• Fragmented sleep:noise, warm room, late screen time, afternoon caffeine, frequent night urination or alcohol can disrupt sleep. 
• Irregular schedule:sleeping at 11 pm on weekdays and 3 am on weekends, or working night shifts, confuses your body clock. 
• Unnoticed insomnia:chronic insomnia may manifest as lethargy and poor concentration in the day, and irritability. 
• Restless legs:a tendency to move your legs during the evening keeps you awake and they can make sleep fitful. It is known that low iron is a contributor. 
• Narcolepsy:A neurological condition characterized by sudden sleep attacks, muscle weakness with laughter, vivid hallucinations when falling asleep, and sleep paralysis. Narcolepsy is often missed for years.
• Idiopathic hypersomnia:A sleep disorder characterized by hypersomnia, including sleeping 10 to 12 hours, long unrefreshing naps, and groggy waking, with no other underlying cause identified.
• Medicines and substances:some antihistamines, sedatives, antidepressants, anti-seizure drugs and blood pressure tablets cause drowsiness. Don't discontinue a prescription drug without your doctor's advice. 
• Medical conditions:iron deficiency, an underactive thyroid, low vitamin B12 or D, diabetes, and kidney, liver, heart or chronic lung disease can all cause sleepiness.
• Depression and anxiety:low mood can lead to less (or more) sleep and anxiety will keep the mind awake at night. 

Several causes can co-exist, which is why a proper evaluation matters.

Discuss these signs with a doctor:

• Often feel sleepy many days for more than 2-3 weeks, even with sufficient sleep
• Snoring, gasping or choking at night, or observed breathing pauses
• Falling asleep in unsafe situations, such as while driving
• Sudden muscle weakness with laughter or emotion or sleep paralysis
• Morning headaches or hard-to-control blood pressure
• Low mood, or sleepiness that began after starting a new medicine

Evaluation typically begins with a thorough sleep history, an examination and blood work including haemoglobin, iron, thyroid function, vitamin B12, vitamin D and blood sugar. A sleep study then confirms or excludes sleep apnea and other sleep disorders, and in some cases, daytime testing is helpful in the diagnosis of narcolepsy or idiopathic hypersomnia. 

Safety note: if you feel sleepy while driving, avoid driving and arrange an evaluation soon.

• Keep a fixed wake-up time, even on weekends.
• Get morning sunlight early in the morning.
• Keep caffeine out of your diet after mid-afternoon and alcohol close to bedtime.
• Keep naps to 20–30 minutes, before mid-afternoon.
• Keep the bedroom dark, cool and quiet with no screens for an hour before sleep.
• Keep a two-week sleep diary of bedtimes, awakenings, naps and sleepiness; it helps your doctor.

Good habits will not help cure a sleep disorder, but they will eliminate everyday causes. If two to three weeks of these changes passes with no change, it is unlikely that habits are the culprit. 

Treatment will vary depending on the cause: CPAP for sleep apnea, CBT-I for insomnia, naps scheduling for narcolepsy and hypersomnolence, and treating the underlying cause of iron, thyroid or mood issues. 

Helplessness in feeling sleepy each day after adequate sleep is common but not normal. Quality of sleep is just as important as quantity and many of the reasons can be treated once they are determined. 

If sleepiness lasts beyond two to three weeks, affects your safety, or comes with snoring, gasping or sudden weakness, seek evaluation early rather than waiting it out.