- Middle ear infection
A middle ear infection puts pressure on the eardrum, causing pain and, sometimes, hearing loss.
- Labyrinthitis
Labyrinthitis, an infection and swelling in the inner ear, and may cause vertigo or hearing loss.
- 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.
- Alzheimer's disease
Alzheimer's disease is type of dementia that causes memory loss, as well as thinking and behavior problems.
- Aspirin poisoning
Aspirin poisoning is a medical emergency and can cause nausea, vomiting, drowsiness and more.
- Transient ischemic attack (mini-stroke)
Transient ischemic attacks cause headache, numbness, tingling, or weakness in the face, arm, or leg, and more.
- Narcolepsy
Narcolepsy is a brain disorder that makes people abnormally sleepy at times during the day.
- Insulin reaction (hypoglycemia)
An insulin reaction is the result of low blood sugar and causes anxiety, hunger, shaking, dizziness, and more.
- Generalized anxiety disorder
Generalized anxiety disorder is a condition in which a person has nearly constant anxiety.
- Panic attack
When someone has a panic attack, that person feels a sudden, intense fear that can't be controlled.
- Benign paroxysmal positional vertigo (BPPV)
Benign paroxysmal positional vertigo is usually a temporary condition that affects balance and causes vertigo.
- Diabetes, type 2
Diabetes can make you feel hungry, tired, or thirsty; you may urinate more than normal and have blurry vision.
- Heart rhythm disorder
Some heart rhythm disorders can cause a fluttering in the chest, shortness of breath, chest pain or dizziness.
- Dehydration (Children)
Dehydration, or not getting enough fluid, causes dry and sticky mouth, tearless crying, and more in children.
- Fainting (vasovagal syncope)
Before fainting, you might feel lightheaded, warm, nausea, a cold sweat, or have tunnel vision.
- Alcohol withdrawal (delirium tremens)
Alcohol withdrawal causes anxiety, depression, headaches, nightmares, fatigue, sweating, and shakiness.
- 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.
- Normal age-related forgetfulness
Age-related forgetfulness is the naturally occurs in many people after age 50.
- Heat stroke (hyperthermia)
Heat stroke is caused by hot weather and results in dizziness, nausea, vomiting, confusion, and a headache.
- Stroke
A stroke occurs when blood and oxygen to the brain are cut off, and causes numbness, confusion, and more.
- Atrial fibrillation
Atrial fibrillation is a heart condition that causes heart palpitations, confusion, dizziness and more.
- Cocaine abuse
Cocaine abuse occurs when a person continues using it despite the social and health problems caused by it.
- Congestive heart failure
People with congestive heart failure can have shortness of breath, fatigue, irregular heartbeat and more.
- High blood pressure (hypertension)
High blood pressure, often asymptomatic, can cause headaches, shortness of breath, nosebleeds, and anxiety.
- Meniere's disease
Meniere's disease is a chronic inner ear condition that causes vertigo or extreme dizziness, and more.
- Pulmonary hypertension
Pulmonary hypertension can cause shortness of breath, a fast heart rate, or lightheadedness.
- Heat exhaustion
Heat exhaustion causes intense thirst, heavy sweating, pale, cool, and moist skin, muscle cramps, and more.
- Concussion
A concussion is an injury to the brain, and may cause confusion, drowsiness, memory loss and headache.
- Diabetes, type 1
Diabetes can make you feel hungry, tired, or thirsty; you may urinate more than normal and have blurry vision.
- Aortic stenosis
Aortic stenosis is a condition of the heart causing shortness of breath, dizziness, or chest pain.
- Benzodiazepine abuse
Benzodiazepines are prescription medications that cause drowsiness, dizziness, blurred vision, and more.
- Anemia, iron deficiency
Anemia , a lack of red blood cells, can cause fatigue, pale skin and gums, brittle nails, irritability, and more.
- Low blood sugar (hypoglycemia)
Low blood sugar, or low glucose levels, causes shakiness, anxiety, clammy skin, irritability, hunger, and more.
- Anemia
Anemia, a lack of red blood cells, can cause fatigue, pale skin, weakness, dizziness, headache and more.
- Anemia, chronic disease
Anemia of chronic disease (ACD) can cause fatigue, pale skin, weakness, dizziness, headache and more.
- Parkinson disease
Parkinson's disease is a disorder of the nervous system causing tremors stiffness and slow movement.
- 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.
- Supraventricular tachycardia
Supraventricular tachycardia is fast heart rhythm starting in one of the upper chambers of the heart.
- Diabetic ketoacidosis
Symptoms of diabetic ketoacidosis include dry mouth, excessive thirst and urination, and more.
- Drug overdose
A drug overdose can be fatal and causes sleepiness, confusion, coma, vomiting, and other symptoms.
- Hyperthyroidism
Hyperparathyroidism can cause fatigue and weakness, increased thirst, impaired thinking, and bone fractures.
- Hyperventilation
Hyperventilation is rapid or shallow breathing usually caused by stress or anxiety.
- 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 (complex partial seizures)
During complex partial seizures, people lose consciousness briefly.
- Aortic regurgitation
Aortic regurgitation, when the aortic valve doesn't close completely, can cause severe heart symptoms.
- Inhalant intoxication
Inhalant intoxication can cause euphoria, disorientation, confusion, slurred speech, dizziness, and more.
- Local anesthetic toxicity
Symptoms of local anesthetic toxicity include lightheadedness, confusion, dizziness, abnormal taste, and more.
- Narcotic abuse
Narcotic abuse can cause fatigue, shallow breathing, anxiety, euphoria, vomiting, confusion, and constipation.
- Night terrors
Night terrors are a sleep disorder that cause people to partially wake up confused and terrified.
- Cryptococcosis
Cryptococcosis is a lung disease causing a wide range of digestive, respiratory and cardiovascular symptoms.
- Dehydration (Adult)
Dehydration, or not getting enough fluid, causes low blood pressure, weakness, dizziness, fatigue, and nausea.
- Carbon monoxide poisoning
Carbon monoxide poisoning can be fatal, symptoms include headache, dizziness, nausea, and vomiting.
- Chemical burns
A chemical burn can cause symptoms ranging from burning and blisters to pain and shortness of breath.
- Brain infection
A brain infection is inflammation of the brain or spinal cord and can cause nausea, fever, seizures and more.
- Toxic shock syndrome
Toxic shock syndrome is a serious bacterial infection and causes fever, low blood pressure, a rash, and more.
- Anemia, hemolytic
Hemolytic anemia occurs when there aren't enough red blood cells in the blood.
- Mad cow disease
Mad cow disease is spread to humans by eating infected cows causing depression, anxiety, psychosis, and more.
- Brain aneurysm
A brain aneurysm is a weak spot in a blood vessel in the brain that balloons and fills with blood.
- Cyanide poisoning
The symptoms of cyanide poisoning include headache, weakness, confusion, nausea, and seizures.
- Small intestine cancer
Small intestine cancer is rare and often has no symptoms, but can cause symptoms in its advanced stages.
- Cat-scratch disease
Cat scratch disease is a bacterial infection caused by a cat scratch or bite.
- Typhoid fever
Typhoid fever is a life-threatening illness and causes fever, general aches and pains, headache, and weakness.
- West nile virus
West Nile virus is an infection spread by mosquitoes, and can cause diarrhea, fever, abdominal pain, and more.
- Shock
Shock causes pale and clammy skin, rapid pulse, low blood pressure, chest pain, confusion, and more.