What is the Ham
The Ham test is a blood test that can help your doctor determine
the condition of the red blood cells in your body. Dr. Thomas Ham designed it.
The test can help your doctor diagnose certain types of acquired and congenital
blood disorders. It involves soaking a blood sample in mild acid to test the
fragility of your blood cells.
Doctors don’t use the Ham test very often. The flow
cytometry test is gradually replacing it.
is the purpose of the Ham test?
One drop of your blood contains millions of red blood cells.
They constantly move through your circulatory system, delivering oxygen your
organs and tissues and removing waste. Healthy red blood cells are vital for
your body’s organs to work properly. Their red color comes from a chemical
called hemoglobin. This is a protein that carries iron and transports oxygen.
Your red blood cells die around every 120 days, and your bone marrow is
constantly producing new ones.
Your doctor may use this test to help diagnose paroxysmal
nocturnal hemoglobinuria (PNH) or congenital dyserythropoietic anemia (CDA).
These are both blood conditions.
do you prepare for the Ham test?
No special preparations are necessary for this test. You
should tell your doctor if you’re taking any blood thinners, such as warfarin
(Coumadin). Your doctor may advise you to stop taking certain medications.
What happens during
the Ham test?
You’ll need to provide a sample of blood from your arm. This involves the
- A healthcare provider will clean the site.
- They’ll insert the needle into your vein and
draw your blood into an attached tube.
- When they’ve drawn enough blood for a sample,
they’ll remove the needle and bandage the site.
- They’ll then send the blood sample to a
laboratory for analysis.
do the results mean?
If the red blood cells don’t become fragile in the acid
solution, your result is normal. A normal result will show as a negative
The following are two conditions that can cause abnormal
Paroxysmal nocturnal hemoglobinuria
PNH is a rare, acquired disease, which means it’s not
genetic. It causes the red blood cells to die prematurely and new cells to
produce incorrectly. The red cells become sensitive to damage by another
substance in the blood. This disorder affects red blood cells, white blood
cells, and platelets. White blood cells fight infection. Platelets are tiny
blood cells that prevent bleeding.
The United States National Library of Medicine notes
that this acquired disease affects both men and women, and most commonly occurs
in early adolescence. The treatment for this disorder if
you have mild symptoms is folate and iron replacement. People also take
steroids for it in more severe cases. In extreme cases, bone marrow transplants
can treat the disorder. The disorder can cause:
- recurring infections
- dark-colored urine, particularly in the morning
- shortness of breath
- abnormally pale skin
- back pain
- abdominal pain
- an increased tendency for venous blood clots, or
Congenital dyserythropoietic anemia
CDA rare blood disease is inherited. Doctors often include it in the group
of anemias that involve reduced hemoglobin synthesis, or thalassemia. It causes
a shortage of red blood cells in the body due to decreased production. This
prevents the circulatory system from delivering enough oxygen to the organs and
tissues. The disorder can cause:
- dizzy spells
- abnormally pale skin
- yellowing of the skin, or jaundice
- liver disease
If you have CDA, your doctor will need to determine which of the three types
CDA type 1 causes mild anemia. Doctors
usually diagnose it in early childhood. It can cause iron overload. The usual
treatment for this type is chelation therapy, which helps remove excess iron
from the body. Yellowing of the eyes and skin is common in people who have this
CDA type 2 may be mild to severe. Doctors usually diagnose
it in the early teens. It can lead to:
- heart disease
CDA type 3 causes relatively mild symptoms. People with this
type usually receive a diagnosis during adulthood. It may lead to vision
impairment and cancer of the white blood cells.
are the risks of the Ham test?
As with any blood test, this test has a minimal risk of causing minor
bruising at the needle site. In rare cases, the vein may swell after blood is
drawn. If this occurs, apply a warm compress to the spot several times each
day. Ongoing bleeding can be a problem if you have a bleeding disorder or if
you’re taking a blood thinner such as warfarin (Coumadin) or aspirin.
for CDA and PNH
Blood transfusions are a common treatment for CDA. You’ll also need to take
medicine to remove the excess iron that builds up in your body. In extreme
cases, a bone marrow transplant may be necessary. Researchers haven’t found gene
therapy to be effective for this type.
The treatment for PNH is iron and folate replacement.
Your doctor may also prescribe steroids. Doctors often use warfarin (Coumadin) to
treat blood clots associated with PNH because it thins the blood and reduces
the risk of thrombosis. If you have an extreme case, you may need a bone marrow