Reference Range(s) Creatinine is the endproduct of creatine metabolism. Creatine is present primarily in muscle and the amount of creatinine produced is related to total skeletal muscle mass. Daily creatinine production is fairly constant except when there is massive injury to muscle. The kidneys excrete creatinine very efficiently and blood levels and daily urinary excretion of creatinine fluctuates very little in healthy normal people.
Schizophrenia is a disease that has several types of symptoms, some of which start earlier than others. The more well-known symptoms, such as hallucinations and delusions, typically start when a man is around 16 to 19 years old or in his early 20s.
-- The probability of developing schizophrenia as the offspring of one parent with the disease is approximately 13 percent. -- The probability of developing schizophrenia as the offspring of both parents with the disease is approximately 35 percent. Onset by Age -- Three-quarters of persons with schizophrenia develop the disease between 16 and 25 years of age. -- Onset is uncommon after age 30, and rare after age 40.