- Fainting (vasovagal syncope)
Before fainting, you might feel lightheaded, warm, nausea, a cold sweat, or have tunnel vision.
- Schizophrenia
Schizophrenia is a serious, chronic mental illness that causes delusional or hallucinogenic thoughts.
- Insulin reaction (hypoglycemia)
An insulin reaction is the result of low blood sugar and causes anxiety, hunger, shaking, dizziness, and more.
- Tension headache
Tension headaches, caused by muscle tension, are marked by pain, pressure and tightness around the head.
- Stroke
A stroke occurs when blood and oxygen to the brain are cut off, and causes numbness, confusion, and more.
- Drug overdose
A drug overdose can be fatal and causes sleepiness, confusion, coma, vomiting, and other symptoms.
- Intracranial hematoma
An intracranial hematoma occurs after a head injury and causes headache, drowsiness, confusion, and more.
- Narcotic abuse
Narcotic abuse can cause fatigue, shallow breathing, anxiety, euphoria, vomiting, confusion, and constipation.
- Carbon monoxide poisoning
Carbon monoxide poisoning can be fatal, symptoms include headache, dizziness, nausea, and vomiting.
- Dementia with Lewy bodies
Dementia with Lewy bodies is a brain disorder that causes problems managing memory and movement.
- Barbiturate abuse
Barbiturates are a type of prescription sedative in which even a slight overdose can cause coma or death.
- Epilepsy (temporal lobe)
Epilepsy is a condition marked by seizures.
- Aseptic meningitis (adult)
Aseptic meningitis, or viral meningitis, can cause fever, headaches, neck pain, nausea, and more.
- Aseptic meningitis (child)
Aseptic meningitis, or viral meningitis, can cause fever, headaches, neck pain, nausea, and more.
- Sunburn
Sunburn causes a reddened, irritated area of skin caused by overexposure to the sun's rays or other UV light.
- Acute sinusitis
Acute sinusitis, an inflammation of the sinuses, causes sinus pain and tenderness, facial redness and more.
- Migraine headache (adult)
Migraines are a common type of headache that can cause severe pain, aura or flashes in vision, and tingling.
- 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.
- Sleep apnea
People with sleep apnea stop and restart breathing multiple times while sleeping.
- Postconcussive syndrome
Postconcussive syndrome occurs when the symptoms of a concussion or other brain injury continue to occur.
- Acute stress reaction
Acute stress reaction symptoms include shortness of breath, anxiety, nervousness, sense of doom and more.
- Epilepsy (tonic clonic or grand mal seizures)
During grand mal or tonic-clonic epileptic seizures, the body becomes rigid and jerky.
- Excessive caffeine use
Excessive caffeine use can cause irritability, difficulty sleeping, anger, depression, and fatigue.
- Caffeine withdrawal
If you suddenly stop drinking caffeine, you get withdrawal symptoms, such as headache, fatigue, and bad mood.
- Malocclusion (bite out of alignment)
Malocclusion is misalignment of the teeth such as underbites, overbites, and crossbites.
- Chronic sinusitis
Chronic sinusitis, or sinus infections, cause a stuffy or runny nose, tooth pain, fever, sore throat and more.
- Migraine headache (children)
Migraines are a common type of headache that can cause severe pain, aura or flashes in vision, and tingling.
- Multiple sclerosis
Multiple sclerosis is a disease of the nervous system causing difficulties with balance, speech, and movement.
- Sporotrichosis
Sporotrichosis is a fungal infection that can cause painless bumps on the fingers, hands, and arms.
- Vitamin B12 deficiency
Vitamin B12 deficiency symptoms include fatigue, pale skin, weakness, sleepiness, numbness, weakness, and more.
- Benzodiazepine abuse
Benzodiazepines are prescription medications that cause drowsiness, dizziness, blurred vision, and more.
- Aspirin poisoning
Aspirin poisoning is a medical emergency and can cause nausea, vomiting, drowsiness 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.
- Anemia, iron deficiency
Anemia , a lack of red blood cells, can cause fatigue, pale skin and gums, brittle nails, irritability, and more.
- Lupus (systemic lupus erythematosus)
Lupus is a chronic autoimmune disease marked by swollen painful joints, a rash, swollen lymph nodes, and more.
- Aortic stenosis
Aortic stenosis is a condition of the heart causing shortness of breath, dizziness, or chest pain.
- 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.
- Head injury
Symptoms of a head injury vary but include headache, nausea, dizziness, memory problems, confusion, and more.
- Dementia in head injury
Dementia resulting from a head injury may cause memory problems, difficulty speaking, and personality changes.
- Thalassemia
Thalassemia is a rare group of genetic blood disorders effecting red blood cells and leading to anemia.
- Cluster headache
Cluster headaches occur one to three times a day for several weeks, and cause severe pain behind the eye.
- Concussion
A concussion is an injury to the brain, and may cause confusion, drowsiness, memory loss and headache.
- Coxsackie virus infection
Coxsackie virus infection can cause many cold-like symptoms as well as blisters on the mouth hands and feet.
- Diabetes, type 1
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.
- Giant cell arteritis (temporal arteritis)
Giant cell arteritis is a blood vessel condition causing headaches located near temples and flu like 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.
- Mononucleosis
Mononucleosis is a viral infection causing extreme fatigue, sore throat, fever, rash, muscle aches, and more.
- Mumps
Mumps is a contagious viral disease that causes painful swelling of the glands that produce saliva.
- Nasal polyps
Nasal polyps, sacs of inflamed tissue in the nasal passages, can cause cold symptoms, snoring, and more.
- Astigmatism
Astigmatism is a common eye problem causing blurry vision, difficulty seeing details and eye strain headaches.
- Lyme disease
Lyme disease is a bacterial infection spread through tick bites; symptoms include rash, fever chills, and more.
- Nonallergic rhinitis
Non-allergic rhinitis causes congestion, sneezing, runny nose, or itchy red eyes for no apparent reason.
- Ocular migraine
Ocular migraine usually refers to a type of migraine that can cause temporary blindness in one eye.
- Cervical (neck) spondylosis
Cervical spondylosis is arthritis of the neck pain and stiffness the neck, shoulder, arm, or chest.
- Depression (Child and Adolescent)
Depression is a painful sadness that interferes with a child's schoolwork, family life, and social activities.
- Diabetic ketoacidosis
Symptoms of diabetic ketoacidosis include dry mouth, excessive thirst and urination, and more.
- Intoxication
Symptoms of intoxication include euphoria, slowed reaction time, dizziness, confusion, numbness, and more.
- Epilepsy (complex partial seizures)
During complex partial seizures, people lose consciousness briefly.
- Brain injury
Brain injuries can cause problems with memory, attention, sight, language, movement, and mood.
- Botulinum toxin (Botox) injection
Botulinum toxin side effects may include pain and tenderness at the injection site, headache, nausea and more.
- 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.
- Allergic reaction
Allergic reaction causes sneezing, runny nose and hives and can lead to anaphylaxis, a whole body reaction.
- Constipation (child)
Constipation is having less than three bowel movements a week, causing hard stools, abdominal pain and more.
- Constipation (adult)
Constipation is having less than three bowel movements a week, causing hard stools, abdominal pain and more.
- Tick bite
A tick-related illness may cause a rash that expands out from the site of the bite, fever, chills, and more.
- Chemical burns
A chemical burn can cause symptoms ranging from burning and blisters to pain and shortness of breath.
- Osteomyelitis (bone infection)
Osteomyelitis is an infection of a bone that causes pain, swelling, and redness.
- Brain infection
A brain infection is inflammation of the brain or spinal cord and can cause nausea, fever, seizures and more.
- Brain aneurysm
A brain aneurysm is a weak spot in a blood vessel in the brain that balloons and fills with blood.
- West nile virus
West Nile virus is an infection spread by mosquitoes, and can cause diarrhea, fever, abdominal pain, and more.
- Lead poisoning
Lead poisoning causes sudden pain on either side of the lower back, urinary issues, nausea, fever, and chills.
- Cyanide poisoning
The symptoms of cyanide poisoning include headache, weakness, confusion, nausea, and seizures.
- Plague
Plague is a rare but deadly bacterial infection causing fever, vomiting, seizures, organ failure, and more.
- Typhoid fever
Typhoid fever is a life-threatening illness and causes fever, general aches and pains, headache, and weakness.
- Anemia, hemolytic
Hemolytic anemia occurs when there aren't enough red blood cells in the blood.
- Toxic shock syndrome
Toxic shock syndrome is a serious bacterial infection and causes fever, low blood pressure, a rash, and more.
- Radiation sickness
Radiation sickness is caused by a high dose of radiation, and causes vomiting, diarrhea, hair loss, and more.
- Endocarditis
Signs of endocarditis, an infection of the heart, include swelling, rash, sinus congestion, nausea, and more.
- Pseudohypoparathyroidism
Pseudohypoparathyroidism is a rare inherited condition that can lead to cramps, muscle spasms, and more.
- Japanese encephalitis
Japanese encephalitis is a disease that causes brain inflammation and swelling.
- Shock
Shock causes pale and clammy skin, rapid pulse, low blood pressure, chest pain, confusion, and more.
- Brain tumor
Primary brain tumors are often benign but can cause seizures, ongoing headaches, or loss of coordination.
- Shingles (herpes zoster)
Shingles is a painful, blistering, skin rash typically found on the back and sides of the chest.
- Bird (avian) flu
Bird flu is spread to people from birds and causes fever, cough, sore throat and muscle aches.
