Self-diagnosis is the process of diagnosing, or identifying, medical conditions in oneself. It may be assisted by medical dictionaries, books, resources on the Internet, past personal experiences, or recognizing symptoms or medical signs of a condition that a family member previously had. For internet searching, it helps to know medical terms for the various signs and symptoms.
Self-diagnosis is prone to error and may be potentially dangerous if inappropriate decisions are made on the basis of a misdiagnosis. Because of the risks, self-diagnosis is officially discouraged by governments, physicians, and patient care organizations. Even physicians are discouraged from engaging in self-diagnosis, because doctors also make mistakes in diagnosing themselves. If the self-diagnosis is wrong, then the misdiagnosis can result in improper health care, including wrong treatments and lack of care for serious conditions.
One of the greatest dangers of self diagnosis in psychological syndromes, is that you may miss a medical disease that masquerades as a psychiatric syndrome. Self-diagnosis also undermines the role of the doctor-which is not the best way to start the relationship. Then there is the fact that we can know and see ourselves, but sometimes, we need a mirror to see ourselves more clearly. By self-diagnosing, you may be missing something that you cannot see. Another danger of self diagnosis is that you may think that there is more wrong with you than there actually is. Self-diagnosis is also a problem when you are in a state of denial about your symptoms.— 
However, self-diagnosis may be appropriate under certain circumstances. All over-the-counter (non-prescription) medications are offered on the assumption that people are capable of self-diagnosis, determining first that their condition is unlikely to be serious and then the possible harm caused by incorrect medication minor. Some conditions are more likely to be self-diagnosed, especially simple conditions such as head lice and skin abrasions or familiar conditions such as menstrual cramps, headache or the common cold.
Complex conditions for which medications are heavily advertised, including conditions like ADHD in adults, present a more challenging situation. Direct-to-consumer marketing of medications is widely criticized for promoting inappropriate self-diagnosis. One other condition that is commonly self-diagnosed is gluten intolerance.
- Medical signs: what an observer can see such as urine color changes (urinalysis), feel...such as fever, or hear on or in the patient. Diarrhea and constipation are signs with numerous causes and even non-medical people can see from the examples on the Bristol Stool Chart.
- Medical Symptoms: what the patient describes about the ailment (list of medical symptoms such as pain).
- Medical tests, to include naked eye (gross) exams of urine, sputum, and stool (feces...see Bristol Stool Chart)
- Medical statistics
- Medical prognosis (prediction of the outcome)
- Mystery & Rare Medical Diagnosis programs (possibly get yourself to one of these):
- NIH Undiagnosed Diseases Program
- NIH Undiagnosed Diseases Network
- Mayo Clinic, Rochester MN**
- Johns Hopkins Remote Second Opinion Plan
- Cleveland Clinic
- North Carolina Rare Disease Network
- UAB Undiagnosed Diseases Program
- Home remedy
- Related mental disorders:
- "Health information on the Internet - Better Health Channel.". Retrieved 2008-03-23.
- "AHRQ WebM&M: Case & Commentary". Retrieved 2008-03-23.
- "A case of self-diagnosis.". Retrieved 2008-03-23.
- "CRICO/RMF - Case Studies - High Risk Areas - Diagnosis - Reliance on Patient's Self Diagnosis Obscures Fatal Condition". Retrieved 2008-03-23.
- "The Dangers of Self Diagnosis", Psychology Today
- Peter D. Stonier; Fletcher, Andrew; Lionel D. Edwards; Fox, Anthony D (2002). Principles and practice of pharmaceutical medicine. New York: Wiley. p. 142. ISBN 0-471-98655-0.
- "Curbside Consultation - August 1, 2006 -- American Family Physician". Retrieved 2008-03-23.
- Conrad, Peter (2007). The Medicalization of Society: On the Transformation of Human Conditions into Treatable Disorders. Baltimore: The Johns Hopkins University Press. p. 59. ISBN 0-8018-8585-X.
- "Self diagnosis from TV drug ads can be dangerous". ajc.com. Archived from the original on March 15, 2007. Retrieved 2008-03-23.
- "AMA (Professionalism) E-5.015 Direct-to-consumer advertisements of prescription drugs". Archived from the original on December 11, 2004. Retrieved 2008-03-23.
- Clinic Handbook: Gastroenterology by J L H Wong (Editor), I. A. Murray (Editor), S. H. Hussaini (Editor), H. R. Dalton (Editor). ISBN 978-1-85996-053-0. Page 151.