- Cataracts
A cataract is a cloudy area in the lens of the eye and can cause blurry or dim vision.
- 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.
- Nearsightedness
Nearsightedness is a common eye problem that causes blurry, distant vision.
- Transient ischemic attack (mini-stroke)
Transient ischemic attacks cause headache, numbness, tingling, or weakness in the face, arm, or leg, and more.
- Diabetes, type 2
Diabetes can make you feel hungry, tired, or thirsty; you may urinate more than normal and have blurry vision.
- Farsightedness (presbyopia)
Presbyopia causes an inability to focus on close objects, and headaches or eyestrain when working or reading.
- Foreign object in the eye
Symptoms of a foreign object in the eye include pain, stinging, itchiness, redness, tearing, bleeding, and more.
- Astigmatism
Astigmatism is a common eye problem causing blurry vision, difficulty seeing details and eye strain headaches.
- Ocular migraine
Ocular migraine usually refers to a type of migraine that can cause temporary blindness in one eye.
- Retinal detachment
Retinal detachment causes floaters in your vision, flashes of light, blind spots, loss of vision, and more.
- Glaucoma
Glaucoma is a group of eye conditions in which fluid builds up in your eye causing gradual vision loss.
- Macular degeneration
Macular degeneration is a painless eye condition that causes you to lose your central vision.
- Diabetic ketoacidosis
Symptoms of diabetic ketoacidosis include dry mouth, excessive thirst and urination, and more.
- Narcolepsy
Narcolepsy is a brain disorder that makes people abnormally sleepy at times during the day.
- Epilepsy (complex partial seizures)
During complex partial seizures, people lose consciousness briefly.
- Stroke
A stroke occurs when blood and oxygen to the brain are cut off, and causes numbness, confusion, and more.
- Giant cell arteritis (temporal arteritis)
Giant cell arteritis is a blood vessel condition causing headaches located near temples and flu like symptoms.
- Pink eye (conjunctivitis)
Pinkeye is redness and swelling of the membrane that lines the eyelid, called the conjunctiva.
- 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.
- Eye injury
There are many types of eye injury, and symptoms include eye pain, burning, irritation, bleeding, and more.
- Heat stroke (hyperthermia)
Heat stroke is caused by hot weather and results in dizziness, nausea, vomiting, confusion, and a headache.
- Diabetes, type 1
Diabetes can make you feel hungry, tired, or thirsty; you may urinate more than normal and have blurry vision.
- Concussion
A concussion is an injury to the brain, and may cause confusion, drowsiness, memory loss and headache.
- High blood pressure (hypertension)
High blood pressure, often asymptomatic, can cause headaches, shortness of breath, nosebleeds, and anxiety.
- Intracranial hematoma
An intracranial hematoma occurs after a head injury and causes headache, drowsiness, confusion, and more.
- Low blood pressure (hypotension)
Low blood pressure, or hypotension, can make you feel lightheaded and dizzy
- 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.
- Sarcoidosis
Sarcoidosis is a rare disease that can cause swelling and hard lumps in the lymph nodes and organs.
- Benzodiazepine abuse
Benzodiazepines are prescription medications that cause drowsiness, dizziness, blurred vision, and more.
- Acute angle-closure glaucoma
Acute angle-closure glaucoma is sudden and causes intense pain in one eye, redness, cloudy vision 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.
- 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.
- 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.
- 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 (simple partial seizures)
During simple partial epileptic seizures, people remain fully conscious, able to respond to external stimuli.
- 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.
- Cryptococcosis
Cryptococcosis is a lung disease causing a wide range of digestive, respiratory and cardiovascular symptoms.
- 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.
- 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.
- Diabetic eye disease
People with diabetes may develop diabetic eye disease, causing vision loss and even blindness.
- Brain infection
A brain infection is inflammation of the brain or spinal cord and can cause nausea, fever, seizures and more.
- Pseudohypoparathyroidism
Pseudohypoparathyroidism is a rare inherited condition that can lead to cramps, muscle spasms, and more.
- Mad cow disease
Mad cow disease is spread to humans by eating infected cows causing depression, anxiety, psychosis, and more.
- 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.
- Brain tumor
Primary brain tumors are often benign but can cause seizures, ongoing headaches, or loss of coordination.
- Toxic shock syndrome
Toxic shock syndrome is a serious bacterial infection and causes fever, low blood pressure, a rash, and more.
- 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.