- Sleep apnea
People with sleep apnea stop and restart breathing multiple times while sleeping.
- Medication reaction or side-effect
Medication side effects include nausea, vomiting, stomach upset, weakness, dizziness, seizures, and more.
- Narcolepsy
Narcolepsy is a brain disorder that makes people abnormally sleepy at times during the day.
- Methamphetamine use
Methamphetamine use causes increased blood pressure, rapid heart rate, enlarged pupils, sweating, and more.
- Sleep deprivation
Sleep deprivation occurs when the lack of restful sleep is severe enough to compromise basic body functions.
- Caffeine withdrawal
If you suddenly stop drinking caffeine, you get withdrawal symptoms, such as headache, fatigue, and bad mood.
- Generalized anxiety disorder
Generalized anxiety disorder is a condition in which a person has nearly constant anxiety.
- Attention deficit hyperactivity disorder (ADHD)
Attention deficit hyperactivity disorder (ADHD) makes it hard to concentrate and focus.
- Bipolar disorder
Bipolar disorder causes extreme mood swings between depression and mania.
- Cocaine abuse
Cocaine abuse occurs when a person continues using it despite the social and health problems caused by it.
- Insomnia
Insomnia symptoms include trouble staying asleep at night, feeling tired during the day, moodiness, and more.
- Restless legs syndrome
Restless leg syndrome causes intense discomfort in your legs and an overpowering urge to move them.
- Schizophrenia
Schizophrenia is a serious, chronic mental illness that causes delusional or hallucinogenic thoughts.
- Alcohol intoxication
Alcohol intoxication, or drunkenness, is marked by impaired judgment, slurred speech, blurred vision and more.
- Alzheimer's disease
Alzheimer's disease is type of dementia that causes memory loss, as well as thinking and behavior problems.
- Anorexia nervosa
Anorexia is an eating disorder associated with low bodyweight developed to cope with emotional problems.
- Bulimia
Bulimia is an eating disorder that involves binging on large quantities of food then purging it by vomiting.
- Asperger syndrome
Asperger syndrome is an autism spectrum disorder often associated with social and communication difficulties.
- Autism
Autism represents a range of neurological disorders that cause social and behavioral problems.
- Dementia in head injury
Dementia resulting from a head injury may cause memory problems, difficulty speaking, and personality changes.
- Dementia with Lewy bodies
Dementia with Lewy bodies is a brain disorder that causes problems managing memory and movement.
- Cocaine withdrawal
Cocaine withdrawal may cause feelings ranging from anxiety, irritability and sleepiness to suicidal thoughts.
- Amphetamine withdrawal
The symptoms of amphetamine withdrawal include depression, fatigue, increased appetite, and sleep problems.
- Epilepsy (temporal lobe)
Epilepsy is a condition marked by seizures.
- Hypocalcemia
Hypocalcemia is a blood condition marked by tingling, muscle spasms and aches, and confusion.
- Hypoparathyroidism
Hypoparathyroidism is a rare condition that can cause muscle twitches, seizures, cramps, tingling, and more.
- Puberty
Puberty is the time when a young person becomes sexually mature.
- Drug withdrawal
Drug withdrawal occurs when you suddenly stop taking a drug; symptoms vary from drug to drug.
- Intoxication
Symptoms of intoxication include euphoria, slowed reaction time, dizziness, confusion, numbness, and more.
- Obsessive compulsive personality disorder
Obsessive compulsive personality disorder causes a person to be preoccupied with order, rules and control.
- Alcohol withdrawal (delirium tremens)
Alcohol withdrawal causes anxiety, depression, headaches, nightmares, fatigue, sweating, and shakiness.