Low Blood Pressure

What is hypotension?

  • Hypotension may be defined as a lower than normal blood pressure readings. There are many causes for hypotension. Some of the main causes may include:
  • Some chemotherapy or biological drugs may cause low blood pressure, such as bleomycin or interleukin. Adverse effects of other drugs, such as rituxamab (Rituxan®) or paclitaxel (Taxol®), may cause blood pressure changes in either direction, higher or lower.
  • You may have low blood counts (anemic), from causes such as recent chemotherapy treatments, or your disease.
  • Certain physical conditions - such as orthostatic hypotension. Orthostatic hypotension is often a result of a disease state, or dehydration.
  • As you get older, or as a result of certain conditions, the central nervous system has a more difficult time regulating blood pressure levels. When you change from a lying to a standing position rapidly, you may feel "faint" or lightheaded, as your blood pressure changes to a level below normal.
  • Orthostatic hypotension may also occur if you are anemic, or dehydrated, as the fluid volume levels in your body are low.
  • Medications - If you are taking certain medications to control your high blood pressure or heart rate, for example, these may cause changes in blood pressure to a lower level.
  • Irregular heart rhythm changes - if your heart is beating irregularly, it potentially causes your blood pressure to be low as a result. The blood is not pumping through your body very effectively, and your body is unable to compensate.
  • Shock - "Shock" may occur from many causes that are related to your heart, lungs, trauma, infection or other diseases. This happens when the circulation of blood is not able to meet your body's needs of oxygen, fluid and nutrients. For example, if you have a severe blood infection, you may develop low blood pressure as a result. Treatment of shock consists of identifying the causes, and trying to correct it.
  • Bleeding - if you are bleeding from your gastrointestinal track, or from some other location, you may be at risk for low blood pressure. This is because you are losing fluids, and fluid levels work to maintain normal blood pressure readings. Severe bleeding may lead to a form of "shock."
  • What are some symptoms of blood pressure changes to look for?
  • You may be overly tired, or very weak (fatigued). It may be hard for you to do any kind of your normal activities.
  • You may feel dizzy or "faint" when you stand up, or change positions slowly. You may feel like you are going "pass out."
  • You may feel sweaty or nauseous, if you think you may faint or lose consciousness.
  • If your low blood pressure changes to a lower rate due to a heart problem, you may feel your heartbeat, or palpitations.
  • You may have a fever, chills or feel ill, if an infection causes your low pressure.
  • You may notice that you are pale in color, or have blood in your stool. This may be due to bleeding from your gastrointestinal tract, or anemia from your disease or chemotherapy treatments.
  • Things you can do to manage hypotension:
  • If you have low blood pressure, changes in position must be performed slowly. Rest for a few minutes in between lying, sitting and standing.
  • Avoid hot environments, such as a shower or a bath, which may cause your blood pressure to be reduced.
  • Avoid alcohol and certain drugs that may cause low blood pressure. Discuss these causes of low blood pressure with your healthcare provider.
  • Drink lots of fluid. Drink 2 to 3 liters of fluid every 24 hours, unless you were told to restrict your fluid intake. This will decrease your chances of being dehydrated, and developing low blood pressure.
  • Monitor for signs of bleeding. If you have tarry black stools, or maroon stools, notify your healthcare provider immediately.
  • Make sure you tell your doctor, as well as all healthcare providers, about any other medications you are taking (including over-the-counter, vitamins, or herbal remedies).
  • Remind your doctor or healthcare provider if you have a history of diabetes, liver, kidney, or heart disease.
  • Drugs that may be prescribed by your doctor:
  • Treatment of low blood pressure is based on correcting the underlying causes.
  • If anti-cancer medication causes your low blood pressure, you will be monitored closely and corrective actions will be taken based on that medication.
  • If you are prescribed a medication for your high blood pressure, and your blood pressure changes too dramatically your dose may be decreased.
  • If you are bleeding, or are dehydrated, your fluid and blood volumes may be low. This potentially causes low blood pressure. Your doctor or healthcare provider will treat this by giving you fluids, plasma, or blood.
  • If you have an infection that causes your low blood pressure, your healthcare providers will correct this with identifying and treating the source of infection in your body. Depending on the source of the infection, the type of antibiotics you will receive may vary.
  • Aspirin - depending on your overall health status, your healthcare provider may prescribe aspirin as a "blood thinner." Aspirin works by preventing platelets in your blood from forming blood clots (anti-platelet). This may be prescribed if you have had a blood clot, irregular heart rhythm, or a heart attack.
  • Beta-blockers - If your low blood pressure changes to a lower rate due to your heart beating irregularly, your doctor will prescribe medications to control your heart rate. Beta-blockers can be used to slow down your heart rate, and improve blood flow through your body. You may take this drug if you have been diagnosed with irregular heartbeats, palpitations, heart failure, or high blood pressure. Some examples of this medication may include: Metoprolol (Lopressor®), propanolol (Inderal®), and atenolol (Tenormin®).
  • A side effect of beta-blockers is low blood pressure. If you are given this medication to control your heart rate, your blood pressure should return to normal. However, you must be careful, and take the medication exactly as directed by your healthcare provider.
  • Digoxin - Also called digitalis, this medication works by slowing down the heart rate, and making it beat more effectively. This will pump blood throughout the body better.
  • Your doctor or healthcare provider should be testing your blood for the levels of digoxin in your blood stream.
  • Midodrine Hydrochloride - This medication may be given to you by your cardiologist or specialist, if you have low blood pressure when you stand up. You will likely receive this medication if your blood pressure changes to a low level when you change positions, and this causes you to feel dizzy, faint, or even "pass out."
  • If you are taking this medication for your low blood pressure, make sure to take it exactly as directed. If your blood pressure changes to a level too high when you lay down as a result of this medication, your healthcare provider may suggest that you sleep on one or two pillows, with the head of the bed elevated.
  • When to call your doctor or health care provider about symptoms of blood pressure changes:
  • Notify your doctor or health care provider immediately and seek emergency help if you have chest pain, chest tightness, or sudden shortness of breath.
  • Notify your doctor or health care provider immediately and seek emergency help if you have a sudden severe headache, slurring speech or weakness on one side of your body and not the other.
  • Shortness of breath, chest pain or discomfort; swelling of your lips or throat should be evaluated immediately- especially if you are taking new medications.
  • Notify your doctor or health care provider within 24 hours if you experience:
  • Fever of 100.5° F (38° C), chills, sore throat (possible signs of infection, especially if you are undergoing chemotherapy).
  • If you "pass out" or lose consciousness as a result of your low blood pressure.
  • Feeling your heart beat rapidly (palpitations).
  • Monitor for signs of bleeding. If you have tarry black stools, or maroon stools, notify your healthcare provider immediately.
  • Any new rashes on your skin, especially if you are taking new medications.
  • Note: We strongly encourage you to talk with your health care professional about your specific medical condition including blood pressure changes, causes and treatments. The information contained in this website about blood pressure changes and other medical conditions is meant to be helpful and educational, but is not a substitute for medical advice.

Related Side Effects

Low Blood Pressure has related side effects:

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