HIV Infection: The Basics Helicobacter pylori Hypertension Heartburn Human leukocyte antigen test Hypolipoproteinemia Hyperimmunoglobulinemia E Syndrome Hives and Angioedema Heart Transplantation Hyperbilirubinemia Heart Defects Human Immunodeficiency Virus (HIV) Infection Hernia Hypertrophic Pyloric Stenosis Hearing Deficits Hereditary Connective Tissue Disorders Hereditary Metabolic Disorders Health Tip: What's Ketoacidosis? Hageman Factor Deficiency Hailey-Hailey Disease Haim-Munk Syndrome Hajdu Cheney Syndrome Hallermann Streiff Syndrome Hand-Foot-Mouth Syndrome Hanhart Syndrome Hantavirus Pulmonary Syndrome Hartnup Disease Hay-Wells Syndrome Headache, Cluster Heart Block, Congenital Heavy Metal Poisoning Hematuria, Benign, Familial Hemimegalencephaly Hemochromatosis, Hereditary Hemophilia B Hemophilia Hemorrhagic Telangiectasia, Hereditary Henoch-Schonlein Purpura Hepatic Fibrosis, Congenital Hepatitis B Hepatitis C Hepatitis, Neonatal Hepatorenal Syndrome Hereditary Exostoses, Multiple Hereditary Hyperphosphatasia Hermansky Pudlak Syndrome Herpes, Neonatal Hers Disease Hiccups, Chronic Hidradenitis Suppurativa Hirschsprung's Disease Histidinemia Hodgkin's Disease Holoprosencephaly Holt Oram Syndrome Homocystinuria Horner's Syndrome HTLV Type I and Type II Human Granulocytic Ehrlichiosis (HGE) Human HOXA1 Syndromes Human Monocytic Ehrlichiosis (HME) Hunter Syndrome Huntington's Disease Hydranencephaly Hydrocephalus Hyper IgD Syndrome Hyper IgE Syndrome, Autosomal Dominant Hyper IgE Syndrome, Autosomal Recessive Hyper IgM Syndrome Hyperexplexia Hyperferritinemia Cataract Syndrome Hyperhidrosis, Primary Hyperkalemia Hyperlipoproteinemia Type III Hyperlipoproteinemia Type IV Hyperostosis Frontalis Interna Hyperoxaluria, Primary (Type I) Hyperprolinemia Type I Hyperprolinemia Type II Hyperthermia Hypochondroplasia Hypoglycemia Hypohidrotic Ectodermal Dysplasia Hypokalemia Hypomelanosis of Ito Hypoparathyroidism Hypophosphatasia Hypophosphatemia, Familial Hypoplastic Left Heart Syndrome Hypotension, Orthostatic Hypothyroidism Hypotonia, Benign Congenital