H. pylori infection
Hairy cell leukemia
Hammertoe and mallet toe
Hamstring injury
Hand foot and mouth disease
Hangovers
Hantavirus pulmonary syndrome
Hashimoto's disease
Hay fever
Head lice
Heart attack
Heart failure
Heat cramps
Heat exhaustion
Heat rash
Heatstroke
Hemangioma
Hemochromatosis
Hemolytic uremic syndrome (HUS)
Hemophilia
Hemorrhoids
Henoch Schonlein purpura
Hepatitis A
Hepatitis B
Hepatitis C
Herniated disk
Hiatal hernia
Hidradenitis suppurativa
High altitude pulmonary edema
High blood pressure (hypertension)
High blood sugar (hyperglycemia)
Hip fracture
Hip labral tear
Hirschsprung's disease
Hirsutism
Histoplasmosis
HIV or AIDS
Hives and angioedema
Hoarding
Hodgkin's lymphoma
Horner syndrome
Hot flashes
Hunter syndrome
Huntington's disease
Hurthle cell cancer
Hydrocele
Hydrocephalus
Hypercalcemia
Hyperglycemia in diabetes
Hyperhidrosis (excessive sweating)
Hyperparathyroidism
Hypersensitivity vasculitis
Hyperthyroidism (overactive thyroid)
Hypertrophic cardiomyopathy
Hypoglycemia
Hyponatremia
Hypoparathyroidism
Hypopituitarism
Hypoplastic left heart syndrome
Hypospadias
Hypothermia
Hypothyroidism (underactive thyroid)