- Cataracts
A cataract is a cloudy area in the lens of the eye and can cause blurry or dim vision.
- Medication reaction or side-effect
Medication side effects include nausea, vomiting, stomach upset, weakness, dizziness, seizures, and more.
- Aspirin poisoning
Aspirin poisoning is a medical emergency and can cause nausea, vomiting, drowsiness and more.
- Stroke
A stroke occurs when blood and oxygen to the brain are cut off, and causes numbness, confusion, and more.
- Low blood sugar (hypoglycemia)
Low blood sugar, or low glucose levels, causes shakiness, anxiety, clammy skin, irritability, hunger, and more.
- Sleep apnea
People with sleep apnea stop and restart breathing multiple times while sleeping.
- Narcotic abuse
Narcotic abuse can cause fatigue, shallow breathing, anxiety, euphoria, vomiting, confusion, and constipation.
- Benzodiazepine abuse
Benzodiazepines are prescription medications that cause drowsiness, dizziness, blurred vision, and more.
- Alcohol intoxication
Alcohol intoxication, or drunkenness, is marked by impaired judgment, slurred speech, blurred vision and more.
- Chronic kidney disease
Chronic kidney disease is a condition of the kidneys that can cause high blood pressure, fatigue, and weakness.
- Dementia in head injury
Dementia resulting from a head injury may cause memory problems, difficulty speaking, and personality changes.
- 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.
- Barbiturate abuse
Barbiturates are a type of prescription sedative in which even a slight overdose can cause coma or death.
- Schizophrenia
Schizophrenia is a serious, chronic mental illness that causes delusional or hallucinogenic thoughts.
- Transient ischemic attack (mini-stroke)
Transient ischemic attacks cause headache, numbness, tingling, or weakness in the face, arm, or leg, and more.
- Intracranial hematoma
An intracranial hematoma occurs after a head injury and causes headache, drowsiness, 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.
- Acute kidney failure
Acute kidney failure is sudden and can cause swelling, frequent dark urination, fatigue, nausea 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.
- Dehydration (Children)
Dehydration, or not getting enough fluid, causes dry and sticky mouth, tearless crying, and more in children.
- Diabetes, type 2
Diabetes can make you feel hungry, tired, or thirsty; you may urinate more than normal and have blurry vision.
- Nearsightedness
Nearsightedness is a common eye problem that causes blurry, distant vision.
- Encephalitis
Encephalitis is swelling and inflammation of the brain from an infection causing sleepiness, fever, and more.
- 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.
- Diabetes, type 1
Diabetes can make you feel hungry, tired, or thirsty; you may urinate more than normal and have blurry vision.
- Astigmatism
Astigmatism is a common eye problem causing blurry vision, difficulty seeing details and eye strain headaches.
- Atrial fibrillation
Atrial fibrillation is a heart condition that causes heart palpitations, confusion, dizziness and more.
- Glaucoma
Glaucoma is a group of eye conditions in which fluid builds up in your eye causing gradual vision loss.
- High blood pressure (hypertension)
High blood pressure, often asymptomatic, can cause headaches, shortness of breath, nosebleeds, and anxiety.
- Macular degeneration
Macular degeneration is a painless eye condition that causes you to lose your central vision.
- 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.
- Multiple sclerosis
Multiple sclerosis is a disease of the nervous system causing difficulties with balance, speech, and movement.
- Sarcoidosis
Sarcoidosis is a rare disease that can cause swelling and hard lumps in the lymph nodes and organs.
- Insulin reaction (hypoglycemia)
An insulin reaction is the result of low blood sugar and causes anxiety, hunger, shaking, dizziness, and more.
- Thyroid storm
A thyroid storm, dangerously high levels of thyroid hormone, causes fever, racing heartbeat, sweating, and more
- Vitamin B12 deficiency
Vitamin B12 deficiency symptoms include fatigue, pale skin, weakness, sleepiness, numbness, weakness, and more.
- Head injury
Symptoms of a head injury vary but include headache, nausea, dizziness, memory problems, confusion, and more.
- Dementia with Lewy bodies
Dementia with Lewy bodies is a brain disorder that causes problems managing memory and movement.
- Hypothyroidism (adult)
Hypothyroidism your body functions slow down, making you gain weight and feel tired all the time.
- Dehydration (Adult)
Dehydration, or not getting enough fluid, causes low blood pressure, weakness, dizziness, fatigue, and nausea.
- Alzheimer's disease
Alzheimer's disease is type of dementia that causes memory loss, as well as thinking and behavior problems.
- Night terrors
Night terrors are a sleep disorder that cause people to partially wake up confused and terrified.
- Transient global amnesia
Transient global amnesia is a sudden loss of memory. Symptoms usually last for hours and then memory returns.
- Epilepsy (temporal lobe)
Epilepsy is a condition marked by seizures.
- Epilepsy (simple partial seizures)
During simple partial epileptic seizures, people remain fully conscious, able to respond to external stimuli.
- Epilepsy (complex partial seizures)
During complex partial seizures, people lose consciousness briefly.
- Cyanide poisoning
The symptoms of cyanide poisoning include headache, weakness, confusion, nausea, and seizures.
- Toxic shock syndrome
Toxic shock syndrome is a serious bacterial infection and causes fever, low blood pressure, a rash, and more.
- Brain tumor
Primary brain tumors are often benign but can cause seizures, ongoing headaches, or loss of coordination.
- Brain infection
A brain infection is inflammation of the brain or spinal cord and can cause nausea, fever, seizures and more.
- Lead poisoning
Lead poisoning causes sudden pain on either side of the lower back, urinary issues, nausea, fever, and chills.
- 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.
- Methanol poisoning
The symptoms of methanol poisoning include trouble breathing, blindness, headache, dizziness, and more.
- Botulinum poisoning
Botulism is a serious illness and can cause abdominal cramps, difficulty breathing, nausea, weakness and more.
- Cavernous sinus thrombosis
Cavernous sinus thrombosis is a blood clot in a sinus and can cause headaches, bulging eyeballs, and more.
- Hypothyroidism (infant and child)
Hypothyroidism in children can cause delayed growth, weight gain, a puffy face, a large tongue, and more.
- Chagas disease
Chagas disease is caused by a tropical parasite and can cause fever, ill feeling, and swelling around the eye.
- Endocarditis
Signs of endocarditis, an infection of the heart, include swelling, rash, sinus congestion, nausea, and more.