Genetic testing is a type of medical test that examines a persons DNA, chromosomes, or proteins to identify changes or mutations that can cause or increase the risk of a genetic disorder. The results of a genetic test can confirm or rule out a suspected genetic condition, help determine a persons chance of developing or passing on a genetic disorder, or provide a diagnosis for a genetic condition such as cystic fibrosis or Huntingtons disease. Genetic testing can be done using a blood or spit sample, and the results are usually ready in a few weeks. There are many different kinds of genetic tests, including gene tests, chromosomal genetic tests, and biochemical genetic tests. Genetic tests can be narrow or large in scope, analyzing an individual DNA building block (nucleotide), one or more genes, or all of a persons DNA (which is known as their genome) . Genetic testing is voluntary, and the decision about whether to be tested is a personal and complex one. A geneticist or genetic counselor can help by providing information about the pros and cons of the test and discussing the social and emotional aspects of testing.