A baby is irritable, has trouble nursing and stops gaining weight. When the infant begins suffering repeated seizures and eventually begins sustaining rapid-onset cerebral ischemia, they are diagnosed with moyamoya disease, and must be treated before they suffer lethal brain damage from the repeated ischemic incidents. A man initially diagnosed with hypoglycemia finds out he's got a tumor in his lung. A woman battling coughs, hives, and muscle weakness, was revealed to have an elevated eosinophil count.

Parents deal with a son with sinus infections and unsteady feet; a woman gains weight and has oily skin, hair loss, body cramps and irritable bowel syndrome. A reverend has trouble sleeping.

A man has suffered from vertigo and ear infections since childhood. A 16-year-old girl has headaches and neck twitching, that led to preeclampsia. A girl has a serious heart condition and stops growing and gaining weight.

A baby's hair appears brittle, and she is slow in developing after a case of whooping cough. Following a tube-tie procedure, Jackie contracted a flesh-eating disease. A boy develops nosebleeds, a sign of something much more terrifying.

A baby shows signs of a genetic disorder. A college graduate developed bloating, decreased sex drive, and yellowing of the eyes. Since childhood, Scott has battled an array of symptoms—severe joint pain, strange rashes, and an inability to sweat. Could his symptoms be related to his kidneys?

Roman was a baby when his parents noticed his head always tilting to one side and his eyes rolling back into his head when he looked up. Could the cause be just one condition? Sharon was an active varsity diver but after a car accident, she developed an unquenchable thirst that would soon take over her life. Peggy lived a healthy and active lifestyle, until one day when the mother of two experienced coughing, joint pain, and swelling.

Nicky was a healthy five-year-old boy until terrifying symptoms landed him in the hospital, fighting for his life. Kristine was a super mom until crippling abdominal pains would change her life forever. Jackie was active until mysterious pains wracked her entire body, eventually becoming so bad that she had to drop out of school.

A baby boy suffers from the same symptoms that killed off male offspring on his mother's side of the family, Could doctors figure out what it is before it's too late? A man in his late thirties experiences a constant, painful burning sensation in his chest, making breathing difficult, but an initial trip to the ER reveals nothing. A woman lives with joint pain, redness in her eyes, and a blood test revealed an elevated anti-nuclear antibody.