kidshealth.org/parent/medical/heart/anemia.html
Anemia, one of the more common blood
disorders, occurs when the level of healthy red
blood cells (RBCs) in the body becomes too low.
This can lead to health problems because RBCs
contain hemoglobin, which carries oxygen to
the body's tissues. Anemia can cause a variety
of complications, including fatigue and stress
on bodily organs.
Anemia can be caused by many things, but the
three main bodily mechanisms that produce it
are:
- excessive destruction of RBCs
- blood loss
- inadequate production of RBCs
Among many other causes, anemia can
result from inherited disorders, nutritional
problems (such as an iron or vitamin
deficiency), infections, some kinds of cancer, or
exposure to a drug or toxin.
Anemia Caused by Destruction of RBCs
Hemolytic ("hemo" means blood, "lytic" means
destroying) anemia occurs when red blood cells are
being destroyed prematurely. (Normally, the lifespan
of RBCs is 120 days. In hemolytic anemia, they have
a much shorter lifespan.) And the bone marrow (the
soft, spongy tissue inside bones that makes new
blood cells) simply can't keep up with the body's
demand for new cells. This can happen for a variety
of reasons. Sometimes, infections or certain
medications - such as antibiotics or antiseizure
medicines - are to blame.
In a condition known as autoimmune
hemolytic anemia, the immune system
mistakes RBCs for foreign invaders and
begins destroying them. Other children inherit
defects in the red blood cells that lead to
anemia. Common forms of inherited
hemolytic anemia include sickle cell anemia,
thalassemia, and glucose-6-phosphate
dehydrogenase deficiency.
Sickle cell anemia is a severe form of anemia
found most commonly in people of African
heritage, although it can affect those of
Caucasian, Saudi Arabian, Indian, and
Mediterranean descent. In this condition, the
hemoglobin forms long rods when it gives up its
oxygen, stretching red blood cells into abnormal
sickle shapes. This leads to premature
destruction of RBCs, chronically low levels of
hemoglobin, and recurring episodes of pain, as
well as problems that can affect virtually every
other organ system in the body. About 1 out of
every 625 African-American children is born with
this form of anemia.
Thalassemia, which usually affects
people of Mediterranean, African, and
Southeast Asian descent, is marked by
abnormal and short-lived RBCs.
Thalassemia major, also called Cooley's
anemia, is a severe form of anemia in
which RBCs are rapidly destroyed and
iron is deposited in the skin and vital
organs. Thalassemia minor involves only
mild anemia and minimal red blood cell
changes.
Anemia Caused by Blood Loss
Blood loss can also cause anemia - whether
it's because of excessive bleeding due to
injury, surgery, or a problem with the blood's
clotting ability. Slower, long-term blood loss,
such as intestinal bleeding from
inflammatory bowel disease (IBD), can also
cause anemia. Anemia sometimes results
from heavy menstrual periods in teen girls
and women. Any of these factors will also
increase the body's need for iron because
iron is needed to make new RBCs.
Anemia Caused by Inadequate Production of RBCs
Aplastic anemia occurs when the bone marrow can't
make enough RBCs. This can be due to a viral
infection, or exposure to certain toxic chemicals,
radiation, or medications (such as antibiotics,
antiseizure drugs, or cancer treatments). Some
childhood cancers can also cause aplastic anemia, as
can certain chronic diseases that affect the ability of the
bone marrow to make blood cells.
Anemia also occurs when the body isn't able to
produce enough healthy RBCs because of an
iron deficiency. Iron is essential to hemoglobin
production. Poor dietary iron intake (or
excessive loss of iron from the body) can lead
to iron deficiency anemia, the most common
cause of anemia in children. Iron deficiency
anemia can affect children at any age, but is
most commonly seen in those younger than
2 years old.
Girls going through puberty also
have a particularly high risk for iron
deficiency anemia because of the
onset of menstruation; the monthly
blood loss increases the amount of
iron they need to consume in their
diets.
Signs and Symptoms of Anemia
If your child has anemia, the first
symptoms might be mild skin paleness,
and decreased pinkness of the lips and
nailbeds. These changes happen
gradually, though, so they may be difficult
to notice. Other common signs of anemia
include:
- irritability
- fatigue
- dizziness, lightheadedness, and a rapid
heartbeat
Preventing Anemia
Whether anemia can be prevented depends
on its cause. Currently, there is no way to
prevent anemia due to genetic defects
affecting the production of RBCs or
hemoglobin.
However, you can take steps to help prevent
iron deficiency, the most common form of
anemia. Before following any of these
suggestions, be sure to talk them over with
your child's doctor.
Cow's milk consumption. During the first 6 months of life,
babies are usually protected against developing iron deficiency
by the stores of iron built up in their bodies pre-birth. But after
month 6, as infants continue to grow, they often don't get enough
iron through breast milk alone or regular cow's milk (which
contains less iron than fortified infant formula). Regular cow's
milk can also cause some infants to lose iron from their
intestines, and drinking lots of it can make an infant less
interested in eating other foods that are better sources of iron.
For these reasons, regular cow's milk is not recommended for
children until they reach 1 year of age and are eating an iron-rich
diet. In addition, your child should not drink more than 24-32
ounces (709-946 ml) of milk each day. If you can't get your child to
eat more iron-rich foods, speak with your child's doctor about
giving your child an iron supplement.
Iron-fortified cereal and
formula. These products can
help ensure that your baby is
getting enough iron, especially
during the transition from
breast milk or formula to solid
foods.
Well-balanced diet. Make sure that your child or teen
regularly eats foods that contain iron. Good choices include
iron-fortified grains and cereals, red meat, egg yolks, leafy
green vegetables, yellow vegetables and fruits, potato skins,
tomatoes, molasses, and raisins. If your child is a
vegetarian, you'll need to make an extra effort to ensure
sufficient iron sources because iron found in meat, poultry,
and fish is more easily absorbed than iron found in plantbased and iron-fortified foods. Also, be aware that certain
food combinations can inhibit or promote absorption of iron.
For example, drinking coffee or tea (including iced tea) with
a meal can significantly lower the amount of iron absorbed.
On the other hand, vitamin C helps the body absorb iron.
www.nlm.nih.gov/medlineplus/ency/article/000560.htm
www.nlm.nih.gov/medlineplus/ency/article/000560.htm
www.nlm.nih.gov/medlineplus/ency/article/000560.htm
Thalassemia
www.dmsc.moph.go.th/webroot/ri/Npublic/p04.htm
Half and half nail
Koilonychia
Yellow nail
Iron Deficiency Anemia
www.nlm.nih.gov/medlineplus/ency/imagepages/3104.htm
Sickel Cell Anemia
www.nlm.nih.gov/medlineplus/ency/imagepages/1223.htm