Alport syndrome, Altitude sickness, Alzheimer's disease, Amenorrhea

Alport syndrome: 

A hereditary disease of the kidneys that pri¬marily affects men, causing blood in the urine, hearing loss and eye problems. Eventually, kidney dialysis or transplant maybe necessary. Alport syndrome affects about one in 5,000 Americans, striking men more often and severely than women. There are several varieties of the syndrome, some occurring in childhood and others not causing symptoms until men reach their 20s or 30s. All varieties of the syndrome are characterized by kidney disease that usually progresses to chronic kidney failure and by uremia (the presence of excessive amounts of urea and other waste products in the blood).

Altitude sickness: 

Altitude sickness is a general term encom¬passing a spectrum of disorders that occur at higher altitudes. Since the severity of symptoms varies with altitude, it is im¬portant to understand the range of the different altitudes that may be involved. High altitude is defined as height greater than 8,000 feet (2,438 m); medium altitude is defined as height between 5,000 and 8,000 feet (1,524-2,438 m); and extreme altitude is defined as height greater than 19,000 feet (5,791 m). The majority of healthy individuals suffer from altitude s.ckness when they reach very high altitudes. In addition, about 20% of people ascending above 9,000 (2,743 m) feet in one day will develop altitude sickness. Children under six years and women in the premenstrual part of their cycles may be more vulnerable. Individuals with preexisting medicalconditions—even a minor respiratory infection—may become sick at more moderate altitudes.

Alzheimer's disease: 

Alzheimer’s disease (AD) is the most com¬mon form of dementia, a neurologic disease characterized by loss of mental ability severe enough to interfere with normal activities of daily living, lasting at least six months, and not present from birth. AD usually occurs in old age, and is marked by a decline in cognitive functions such as remembering, reasoning, and planning.
Amblyopia: Amblyopia is an uncorrectable decrease in vision in one or both eyes with no apparent structural abnormality seen to explain it. It is a diagnosis of exclusion, meaning that when a decrease in vision is detected, other causes must be ruled out. Once no other cause is found, amblyopia is the diagnosis. Generally, a difference of two lines or more (on an eye-chart test of visual acuity) between the two eyes ora best corrected vision of 20/30 or worse would be defined as amblyopia. For example, if someone has 20/20 vision with the right eye and only 20/40 with the left, and the left eye cannot achieve better vision with corrective lenses, the left eye is said to be amblyopic. Amebiasis: Amebiasis is an infectious disease caused by a para¬sitic one-celled microorganism (protozoan) called Entamoeba histolytica. Persons with amebiasis may experience a wide range of symptoms, including diarrhea, fever, and cramps. The disease may also affect the intestines, liver, or other parts of the body.

Amenorrhea: 

The absence of menstrual periods is called amen¬orrhea. Primary amenorrhea is the failure to start having a period by the age of 16. Secondary amenorrhea is more com¬mon and refers to either the temporary or permanent ending of periods in a woman who has menstruated normally in the past. Many women miss a period occasionally. Amenorrhea occurs if a woman misses three or more periods in a row. The absence of menstrual periods is a symptom, not a disease. While the average age that menstruation begins is 12, the range varies. The incidence of primary amenorrhea in the United States is just 2.5%. Some female athletes who participate in rowing, long distance running, and cycling, may notice a few' missed periods. Women athletes at a particular risk for developing amenorrhea include ballerinas and gymnasts, who typically exercise strenuously and eat poorly.