This section has been reviewed and approved by the PLWC Editorial
Hypercalcemia is an unusually high level of
calcium in the blood. Hypercalcemia can be life
threatening and is the most common metabolic disorder associated with
cancer, occurring in 10% to 20% of people with cancer. While most of the
calcium in the body is stored in the bones, about 1% of the body's
calcium circulates in the bloodstream. Calcium is important for many
bodily functions, including bone formation, muscle contractions, and
nerve and brain function.
The level of calcium in the blood is controlled by many factors,
including the parathyroid hormone (a hormone released by the parathyroid
glands) and the kidneys (which remove excess calcium from the blood).
Cancer can cause high levels of blood calcium in different ways:
- Cancers that affect the
bone directly (such as multiple myeloma or
leukemia) or cancers that commonly spread to the bone (such as
breast cancer) cause the bone to break down, releasing excess
calcium into the blood.
- Some cancers produce parathyroid
hormone-related protein, a chemical very similar to parathyroid
hormone that causes the bone to release calcium into the blood.
- Some cancers affect the
ability of the kidneys to remove excess calcium.
- Dehydration caused by
nausea and vomiting also makes it difficult for the kidneys to
remove calcium properly.
- Lack of activity can
cause bone to break down, releasing calcium into the blood.
The cancers most likely to cause hypercalcemia
include breast cancer, lung cancer, and multiple myeloma.
Other cancers that can cause hypercalcemia
include lymphoma, leukemia, kidney cancer, head and neck cancer, and
The symptoms of hypercalcemia often develop
slowly and can be very similar to the symptoms of cancer or cancer
treatments. The seriousness of symptoms is often unrelated to the actual
level of calcium in the blood, and many patients have no symptoms at all.
Older patients usually experience more symptoms than younger patients.
People with hypercalcemia may experience the
- Loss of appetite,
nausea, and vomiting
- Constipation and
- Increased thirst and
- Tiredness, weakness, and
- Changes in mental
status, including confusion, disorientation, and difficulty thinking
Finally, severe hypercalcemia
can be associated with kidney stones, irregular heartbeat or heart
attack, and eventually loss of consciousness and coma.
Diagnosis and treatment
Hypercalcemia is diagnosed through a blood test
to check the level of calcium. Other blood tests may be done to check
kidney function. Patients with mild hypercalcemia
who have no symptoms are treated with extra fluids, usually given through
a vein, which help the kidneys remove excess calcium. Patients with moderate
or severe hypercalcemia can be treated in
- Treating the underlying
- Replacing fluids
medications to help stop the breakdown of bone, including bisphosphonates, calcitonin
or Miacalcin), plicamycin
(Mithracin), and gallium nitrate (Ganite)
- Administering other
medications, including steroids and phosphates (steroids decrease
the breakdown of bone and the uptake of calcium from food;
phosphates slow down the breakdown of bone and move calcium from the
blood to other tissues)
- Using dialysis to treat
patients with kidney failure
Hypercalcemia is a serious disorder and can be
life threatening. Patients and their families should be familiar with the
symptoms of hypercalcemia and report any
symptoms to their doctor. Treatment not only improves symptoms, but also
improves quality of life and may make it easier to complete cancer
treatment. Unless there is effective anticancer treatment for the
underlying cancer, hypercalcemia suggests that
a patient is approaching the last weeks of life.
In addition to getting treatment from your doctor, the following tips can
help prevent hypercalcemia or prevent it from
- Drink fluids
- Control nausea and
- Walk and be active,
which helps prevent bone from breaking down
- Check with your doctor
before taking any medications, as some may make hypercalcemia
Note: Hypercalcemia is not
related to having too much calcium in the diet, so reducing calcium
intake by eating fewer dairy products and other high-calcium foods does