A baby boy has bouts of vomiting and diarrhea from the day of his birth; a young woman experiences blackouts after she hits puberty.

Doctors can't pinpoint the cause of the array of debilitating ailments a woman has been suffering from for more than 50 years.

A teenager is rushed to the hospital after taking aspirin to help alleviate altitude sickness; a woman has pain in her arm that mysteriously spreads.

Amanda Coveler, a woman who successfully gives birth to a second daughter after two miscarriages, faces challenges after giving birth.

A woman and her husband decide to start a family after numerous negative pregnancy tests; a man appears to suffer an embolism

A three-year-old's unexplained vaginal bleeding sends her parents searching for answers to help their baby girl. Also, a student plagued by cramps is unable to hold her food down.

A mother rushes her toddler to hospital when she loses the ability to walk or stand. Plus, a runner tries to sleep off a numbness in his foot, but finds the sensation spreading.

Since birth, Ricky is plagued by respiratory infections and a bizarre inability to grow. Noel is a healthy, active man until mysterious spasms start taking over his life.

Harry's body starts to undergo a mysterious transformation. Sadie finds herself on the brink of starvation after her doctor dismisses her complaints.

A young man has strange growths; toddler rapidly gains weight.

A woman starts growing uncontrollably. A boy coughs up raspberry-like growths.

When Kylie is born struggling to breathe, doctors aren't sure whether they will find a cure. Also, athlete Michael is left fighting for his life when a sore throat turns deadly.

After blisters appear all over the body of young Julie McCawley, she appears to have Stevens-Johnson syndrome; Conor Heybach's weight gain and uncontrollable appetite is a mystery until a doctor discovers he has Prader-Willi syndrome.

An 18-month-old baby suddenly starts screaming one afternoon in the pool, and begins exhibiting extremely painful symptoms when exposed to sunlight, with porphyria later found to be the culprit. A mother of two children begins to suffer a series of very debilitating headaches.

After moving houses, and months of strange behavior, 12-year-old Sammy stops walking and only hops; the doctors are the only hope to discover the cause of his bizarre symptoms. He is eventually diagnosed with PANDAS, a condition in which antibodies mistake his brain for Streptococcus bacteria.

Diane finds two small, red bumps on her foot; within hours her foot is swollen and appears black and blue; despite undergoing tests, the medical team has no diagnosis.

After suffering a series of debilitating incidents believed to be the result of Crohn's disease, Karen, an albino, has to have most of her colon removed. Several decades later, at the age of 38, she receives a phone call from someone who suggests she is suffering from a rare and fatal disease, Hermansky-Pudlak syndrome, which is also the cause of her albinism.

A girl sleeps for ten days in a row, but tests are normal and doctors are perplexed; a marathon runner experiences unexplainable fatigue.

June has a biopsy and, when a mark appears on the site, she has surgery, leaving her with a growing open wound. Her doctor diagnoses her with a flesh eating virus. Can June's life be saved?

When Jeanne fails to hit puberty, doctors discover that something truly bizarre is the cause; analysis of her DNA finds that she is genetically male, possessing Y chromosomes, but due to the rare genetic disorder Swyer syndrome, she appears outwardly female. Mary is stricken with a collapsed lung and breathing problems.

Nicole is a teenager who feels excruciating pain in her jaw and her face starts to sink, with her affliction later found to be the result of Parry-Romberg syndrome. Kevin thinks he has food poisoning, but he starts to lose motor coordination.

Carole, a 65-year-old woman, has a hard time walking in a straight line; Sonya and Sherwood are delighted with their second daughter, but they begin to worry when the baby does not stop crying. When a particularly unusual symptom emerges, followed by uncontrollable seizures, it is discovered that the infant is affected by maple syrup urine disease.

By the time Adrian is in high school his right leg weighs 150 lb (68 kg) and limits his mobility. Kathy is struggling to treat a rash and is experiencing weight loss. Can doctors help?

A baby who cries and holds her cheek; a woman who gained 100 pounds in three months and developed severe acne; and an avid athlete struggling to catch his breath. Featuring trigeminal neuralgia, polycystic ovary syndrome and alpha-1 antitrypsin deficiency.

A very active 41-year-old bodybuilder realizes that a strange lump has grown in her jaw while training for a competition; a boy has infrequent bowel movements.