Hematology is the study of the blood and blood disorders in the body. A hematologist is a physician who has expertise in diseases of the blood and bone marrow, and treats vascular and clotting problems. The hematologist also treats blood disorders such as hemophilia, leukemia, lymphoma, anemia and sickle cell disease.

Physicians in this specialty treat patients suffering from numerous diseases and illnesses, but some of the most common are Malaria, lymphoma, Non-Hodgkin's Lymphoma, Myelomas, Evans' syndrome, AIDS, Leukemia, hemophilia, Thrombocytopenia, Sickle-cell disease, Myeloma, Pernicious anemia, Hodgkin's disease, Thalassemia, Myelofibrosis, Infectious mononucleosis, Agranulocytosis, Systemic lupus erythematosus (SLE), Megaloblastic anemia, and Autoimmune hemolytic anemia.

Once properly diagnosed, practitioners can perform numerous procedures on patients including Chemotherapy, Bone marrow transplant, blood transfusion, radiotherapy, Intramuscular injections, Anticoagulation therapy, and Venesection.

To diagnose patients with possible illnesses and diseases, specialists will often perform one of many tests including Coombs test, D-dimer, Prothrombin time, Bone marrow biopsy, Protein electrophoresis, serum Ferritin level, Partial thromboplastin time, Vitamin B12 and Folate levels, Erythrocyte sedimentation rate (ESR), Blood film, Full blood count, and Hemoglobin electrophoresis.

Doctor density varies by specialty and location. California has 1,298 practicing hematologists. Broken out by city, hematology doctor density in Alhambra is 3, in Anaheim is 19, in Antioch is 4, in Arcadia is 7, in Berkeley is 10, in Beverly Hills is 21, in Burbank is 9, in Campbell is 4, in Chico is 3, in Chula Vista is 10, in Concord is 8, in Corona is 6, in Covina is 3, in Culver City is 3, in Downey is 7, in Duarte is 61, in Encinitas is 9, in Escondido is 7, in Eureka is 3, in Folsom is 5, in Fountain Valley is 16, in Fremont is 6, in Fresno is 34, in Fullerton is 3, in Garden Grove is 5, in Gardena is 2, in Glendale is 16, in Glendora is 7, in Hanford is 2, in Hawthorne is 4, in Hemet is 5, in Huntington Beach is 14, in Irvine is 10, in La Mesa is 5, in Laguna Hills is 6, in Lancaster is 9, in Lodi is 1, in Loma Linda is 13, in Lompoc is 2, in Long Beach is 33, in Los Alamitos is 13, in Los Angeles is 193, in Lynwood is 2, in Madera is 2, in Manteca is 2, in Mission Viejo is 6, in Modesto is 11, in Montebello is 5, in Monterey is 10, in Monterey Park is 9, in Mountain View is 5, in Newport Beach is 16, in Novato is 2, in Oakland is 14, in Oceanside is 6, in Orange is 38, in Oxnard is 10, in Palo Alto is 61, in Paramount is 1, in Pasadena is 19, in Pleasanton is 6, in Pomona is 5, in Poway is 2, in Rancho Mirage is 10, in Redding is 3, in Redondo Beach is 7, in Riverside is 20, in Roseville is 15, in Sacramento is 67, in Salinas is 3, in San Bernardino is 4, in San Diego is 78, in San Francisco is 73, in San Gabriel is 8, in San Jose is 21, in San Leandro is 5, in San Luis Obispo is 7, in San Mateo is 5, in San Ramon is 3, in Santa Ana is 5, in Santa Barbara is 14, in Santa Maria is 7, in Santa Monica is 32, in Santa Rosa is 16, in Scotts Valley is 1, in Signal Hill is 1, in Simi Valley is 6, in Solvang is 4, in South San Francisco is 6, in Stockton is 8, in Sunnyvale is 3, in Torrance is 27, in Upland is 6, in Visalia is 6, in Vista is 8, in Walnut Creek is 23, in West Covina is 7, in West Hollywood is 15, in Westlake Village is 4, and in Whittier is 6.

California’s population is 36,142,137, and it is America’s third largest and most populous state. It also claims the highest and lowest altitudes in the lower 48 states. The lowest point in the country, Death Valley, is also home to the nation’s highest recorded temperature, 134 degrees. Tourists flock to this state for its many outdoor activities and attractions, including Universal Studios, Disneyland, Rodeo Drive shopping, the Golden Gate Bridge in San Francisco, wine country tours, and California’s numerous beaches and parks. Los Angeles is the nation’s second largest city, but California’s capital is Sacramento. The giant sequoias in California’s forests are among the oldest living things in the world, and a redwood in the Redwood National Park is said to be the world’s tallest tree, at 365 feet. California achieved statehood in 1850, and was named the Golden State after the beginning of the Gold Rush in 1848.

According to 2005 Census estimates, California has a population of 36,132,147. Of this population, 9,308,563 are under the age of 18 and 3,827,038 are at or above the age of 65.