Tinnitus is popularly known as a ‘ringing in the ears’, but the term actually refers to any perception of noise in the absence of a true external sound. This can take many forms, including buzzing, ticking and whistling as well as ringing. Approximately 1 in 3 people experience tinnitus at least once in their lifetime, and the worldwide prevalence is approximately 10 percent. Tinnitus can range...
Melanoma accounts for less than 5 percent of skin cancer cases, but is responsible for more than 75 percent of skin cancer deaths. At a time when the incidence of many cancers is falling, the rate of melanoma is rising. The World Health Organization estimates that approximately 160,000 new cases of melanoma are diagnosed each year, and that melanoma is responsible for approximately 48,000 deaths...
Unintended pregnancies are pregnancies that are unplanned or unwanted at the time of conception. It is estimated that as many as 41 percent of the 208 million worldwide pregnancies in 2008 were unintended. These pregnancies can be associated with increased risk for both the mother and infant; lack of preconception planning and prenatal care can lead to behaviors linked to birth defects, including...
The pancreas is a large gland located in the abdomen adjacent to the stomach. It plays an important role in the digestion and utilization of food. Digestive enzymes secreted by the pancreas help to break down the carbohydrates, fats and proteins in foods, allowing them to be absorbed by the small intestine (first portion of the bowel). The pancreas also releases insulin into the bloodstream...
Colorectal cancer is the third most common cancer in men worldwide, and the second most common cancer in women. It is the fourth most common cause of cancer death worldwide, accounting for approximately 8% of cancer deaths. However, early detection and surgical removal of colon cancer offers a high potential for curing the disease, with a 93% 5-year survival rate for Stage I cancers. This...
Posttraumatic stress disorder (PTSD) is a severe anxiety disorder triggered by experiencing or witnessing a traumatic event, such as an accident, war, unexpected death of a loved one or serious assault. The intense fear and horror associated with such traumatic events is expected to cause strong reactions in most people, including nervousness, anger and fear. Usually, these reactions decrease...
Breast cancer is the most common cancer in women worldwide, and the leading global cause of cancer death in women. The lifetime risk of breast cancer is approximately 1 in 8. In 2010, more than 1.6 million new cases of breast cancer were diagnosed worldwide. Breast cancer staging The prognosis (probable outcome) of breast cancer depends heavily on the stage of breast cancer at diagnosis. Staging...
Parkinson’s disease is a devastating brain disorder causing a number of neurological symptoms including tremors, muscle stiffness and slowing of movement. The disease usually strikes individuals over the age of 50, although young-onset forms of Parkinson’s can occasionally run in families. Parkinson’s is progressive, meaning that the symptoms continue to worsen over time. What starts as a mild...
Alzheimer’s disease is the most common form of dementia, a term describing the loss of memory and other cognitive functions to the point of interfering with daily life. Alzheimer’s is predominantly a disease of late middle and old age, affecting up to 13% of individuals over the age of 65. The disease is progressive, meaning that the symptoms of memory loss, personality change and confusion...
Cardiovascular disease is the leading cause of death worldwide, responsible for an estimated 30% of global deaths in 2008. Most of these deaths result from coronary artery disease and stroke. Coronary artery disease refers to the narrowing of the coronary arteries (the arteries providing blood supply to the heart) by a substance called atheromatous plaque. These plaques are formed from lipid...
Margaret McKernan, MD, PhD is a practicing diagnostic radiologist and medical writer. She has an MD, PhD degree in Neuroscience from the University of Texas Medical Branch, and completed her training in Radiology at Wake Forest University Baptist Medical Center. She also completed additional fellowship training in Abdominal Imaging at Massachusetts General Hospital.