- 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.
- Schizophrenia
Schizophrenia is a serious, chronic mental illness that causes delusional or hallucinogenic thoughts.
- Aspirin poisoning
Aspirin poisoning is a medical emergency and can cause nausea, vomiting, drowsiness and more.
- Benzodiazepine abuse
Benzodiazepines are prescription medications that cause drowsiness, dizziness, blurred vision, 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.
- 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.
- 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.
- Dementia in head injury
Dementia resulting from a head injury may cause memory problems, difficulty speaking, and personality changes.
- Narcotic abuse
Narcotic abuse can cause fatigue, shallow breathing, anxiety, euphoria, vomiting, confusion, and constipation.
- Aortic regurgitation
Aortic regurgitation, when the aortic valve doesn't close completely, can cause severe heart symptoms.
- Heat exhaustion
Heat exhaustion causes intense thirst, heavy sweating, pale, cool, and moist skin, muscle cramps, 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.
- Atrial fibrillation
Atrial fibrillation is a heart condition that causes heart palpitations, confusion, dizziness and more.
- Diabetes, type 1
Diabetes can make you feel hungry, tired, or thirsty; you may urinate more than normal and have blurry vision.
- Pulmonary hypertension
Pulmonary hypertension can cause shortness of breath, a fast heart rate, or lightheadedness.
- Transient ischemic attack (mini-stroke)
Transient ischemic attacks cause headache, numbness, tingling, or weakness in the face, arm, or leg, and more.
- 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.
- Hyperventilation
Hyperventilation is rapid or shallow breathing usually caused by stress or anxiety.
- Insulin reaction (hypoglycemia)
An insulin reaction is the result of low blood sugar and causes anxiety, hunger, shaking, dizziness, and more.
- Low blood sugar (hypoglycemia)
Low blood sugar, or low glucose levels, causes shakiness, anxiety, clammy skin, irritability, hunger, and more.
- Aortic stenosis
Aortic stenosis is a condition of the heart causing shortness of breath, dizziness, or chest pain.
- Anemia, iron deficiency
Anemia , a lack of red blood cells, can cause fatigue, pale skin and gums, brittle nails, irritability, and more.
- Supraventricular tachycardia
Supraventricular tachycardia is fast heart rhythm starting in one of the upper chambers of the heart.
- Acute kidney failure
Acute kidney failure is sudden and can cause swelling, frequent dark urination, fatigue, nausea 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.
- 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.
- Chronic kidney disease
Chronic kidney disease is a condition of the kidneys that can cause high blood pressure, fatigue, and weakness.
- 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.
- Barbiturate abuse
Barbiturates are a type of prescription sedative in which even a slight overdose can cause coma or death.
- Carbon monoxide poisoning
Carbon monoxide poisoning can be fatal, symptoms include headache, dizziness, nausea, and vomiting.
- Depression (Adult)
Depression is a painful sadness that interferes with daily life and includes hopelessness, anxiety, and more.
- Chemical burns
A chemical burn can cause symptoms ranging from burning and blisters to pain and shortness of breath.
- Cyanide poisoning
The symptoms of cyanide poisoning include headache, weakness, confusion, nausea, and seizures.
- Anemia, hemolytic
Hemolytic anemia occurs when there aren't enough red blood cells in the blood.
- Small intestine cancer
Small intestine cancer is rare and often has no symptoms, but can cause symptoms in its advanced stages.