Sickle cell disease
A genetic blood disorder caused by the presence of an abnormal form of hemoglobin. These hemoglobin molecules tend to aggregate after unloading oxygen forming long, rod-like strictures that force the red cells to assume a sickle shape. Unlike normal red cells, which are usually smooth and malleable, the sickle red cells cannot squeeze through small blood vessels. When the sickle cells block small blood vessels, the organs are deprived of blood and oxygen. This leads to periodic episodes of pain and damages the vital organs. Sickle red cells die after only about 10 to 20 days. Instead of the usual 120 days or so. Because they cannot be replaced fast enough, the blood is chronically short of red cells, causing anemia. The gene for sickle cell anemia must be inherited from both parents for the illness to occur in children. A child with only one copy of the gene may have sickle-cell traits but no symptoms of illness.
Read Also:
- Sickle cell trait
The condition in which a person has only one copy of the gene for sickle cell (and is called a sickle heterozygote) but does not have sickle cell disease (which requires two copies of the sickle cell gene). If two people with sickle cell trait mate and have children together, each of their children has […]
- Sickle hemoglobin
Hemoglobin S, the most common type of abnormal hemoglobin and the basis of both sickle cell trait and sickle cell anemia. Hemoglobin S differs from normal adult hemoglobin (hemoglobin A) only by a single amino acid substitution (There is the substitution of the amino acid valine for the amino acid glutamine in the 6th position […]
- Sickness, acute mountain (AMS)
Acclimatization and Illnesses” by Rick Curtis).
- Sickness, morning
Nausea and vomiting of pregnancy. Morning sickness is a misnomer, because it can occur at any time of the day (though not at night during sleep) and it is not a sickness. It is a normal characteristic of early pregnancy. Morning sickness is now believed to be a good thing since it appears associated with […]
- Sickness, motion
A disorder of the sense of balance and equilibrium and, hence, the sense of spatial orientation that is caused by repeated motion such as from the swell of the sea, the movement of a car, or the motion of a plane in turbulent air. Motion sickness is due to irritation of a portion of the […]