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 1,275 practicing hematologists. Broken out by city, hematology doctor density in Sacramento is 65, in Saint Helena is 1, in Salinas is 4, in San Anselmo is 2, in San Bernardino is 4, in San Clemente is 2, in San Diego is 76, in San Fernando is 1, in San Francisco is 69, in San Gabriel is 7, in San Jose is 20, in San Juan Capistrano is 1, in San Leandro is 5, in San Luis Obispo is 7, in San Mateo is 5, in San Pablo is 1, in San Pedro is 2, in San Rafael is 2, in San Ramon is 3, in Santa Ana is 5, in Santa Barbara is 13, in Santa Clara is 8, in Santa Clarita is 2, in Santa Cruz is 4, in Santa Maria is 7, in Santa Monica is 31, in Santa Rosa is 18, in Scotts Valley is 1, in Seal Beach is 1, in Seaside is 1, in Sebastopol is 1, in Sherman Oaks is 4, in Signal Hill is 1, in Simi Valley is 4, in Solvang is 2, in Sonora is 4, in Soquel is 2, in South Pasadena is 1, in South San Francisco is 6, in Stanford is 72, in Stockton is 8, in Sun City is 3, in Sun Valley is 1, in Sunnyvale is 3, and in Sylmar is 8.

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.