If an early embryo only partially separates and two babies develop, they remain physically connected — most often at the chest, abdomen or pelvis.
Disease
Enlarged spleen (splenomegaly)
Learn about what your spleen does and what can happen if it becomes enlarged.
Disease
Noonan syndrome
This genetic condition stops typical development in parts of the body. It may include unusual facial features, short height, heart problems or other issues.
Disease
Prader-Willi syndrome
This rare genetic condition leads to physical, mental and behavioral problems, including being hungry all the time.
Disease
Inherited metabolic disorders
Caused by gene changes, these disorders affect the body's ability to change food into energy. They also affect how energy is used, such as for cell repair.
Disease
Turner syndrome
Turner syndrome affects only females as the result of a missing or partially missing X chromosome, causing a variety of medical and developmental problems.
Disease
Hay fever
Find out more about how to diagnose and get relief from this common condition that can make you feel awful, seasonally and year-round.
Disease
Shellfish allergy
It's possible to be allergic to some types of shellfish without reacting to other types. Learn more about this common food allergy.
Disease
Umbilical hernia
Learn about this condition in which your intestines create a bulge near your navel.
Disease
Perimenopause
Discover effective treatments and learn self-care strategies for hot flashes, night sweats, vaginal dryness and other perimenopause symptoms.
Disease
Spinal cord tumor
Spinal cord tumors can cause serious problems such as pain and paralysis. Find out about diagnosis and treatment.
Disease
Broken toe
Pain when wearing shoes and difficulty walking can signal a broken toe — so see your health care provider to help it heal and ease pain.