When I was younger, every time I got a bloody nose, I was convinced that I had Leukemia (thanks to A Walk to Remember and K-dramas). My mother assured me that I didn't have cancer but also remarked that I was being a hypochondriac.
A hypochondriac is a person who suffers from hypochondriasis (more commonly referred to as hypochondria)--a somatoform disorder that gives one the belief that they are suffering from a severe physical ailment (Lillienfeld 598). A somataformawhata? Simply put, a somatoform disorder is a mental illness that causes unexplained physical pain and is often linked with other psychotic disorders such as mood, anxiety, personality, and eating disorders (Oyama).

There are three criteria that symptoms must meet for a patient to be diagnosed with somatoform disorder: (1) cannot be explained as the effects of a substance, a general medical condition, or another mental illness; (2) cannot be outcomes of a factitious disorder--unconscious claims for internal gains such as wanting to be sick--or malingering--unconscious claims for external gains such as financial or legal benefits; and (3) must pose a significant strain on the patients' livelihood (social, occupational, ect.) (Oyama). In theory, this should minimize fraudulent claims.
To summarize: Hypochondriasis is a somatoform disorder and my mom was exaggerating when she called me a Hypochondriac. My bloody noses did not effect my childhood more than a few bloody stains on T-shirts and pillowcases, and I did not get any other severe symptoms that were unexplainable--the bloody noses could have easily been due to dry air. Aha! Mother is not always right.
Sources:
Oyama, Oliver, Catherine Paltoo, and Juliane Greengold. Somataform Disorders. American Family Physician, 2007. Web. 25 Jan. 2012.
Lilienfeld, Scott, et al. Psychology: From Inquiry to Understanding, Second Edition. Massachusetts: Allyn & Bacon, 2010.

The funny thing is, that my mother also called me a hypochondriac...I was prone to injury and accidents, all the time. Every time I got cut or gouged or broken, I would always ask how severe it was...out of fear that I would keep bleeding or need surgery.
At 5 years old I didn't fit any of the mentioned criteria, so I wasn't a hypochondriac...so we proved them both wrong!
It might just a child's reaction though, thinking that things are worse than they are. Just because we haven't had the amount of experience with the world.