The Blood Pressure Association, the UK's leading blood pressure charity dedicated to preventing stroke and heart attack, defines low blood pressure as a reading lower than 90/60. Although this condition is natural for some and is not a cause for concern, for others low blood pressure stems from medications or certain health conditions that causes dizziness and a feeling of lightheadedness. Being aware of these causes may help prevent low blood pressure.
Being Pregnant
The Mayo Clinic and the American Heart Association agree that pregnancy is one of the causes of low blood pressure. This is most likely to occur within the first 24 weeks when the circulatory system expands quickly, causing blood pressure to drop. The Mayo Clinic also says that the systolic pressure, or the top number, commonly decreases by as much as 5 to 10 points and that the diastolic, or the lower number, can decrease up to 10 or 15 points. This is completely normal, and after a woman gives birth her blood pressure typically returns to pre-pregnancy numbers.
Heart Conditions
The American Heart Association (AHA) says certain heart conditions can cause your blood pressure to drop. These include problems with heart valves, bradycardia (a low heart rate), heart failure and heart attacks. All of these result in the heart's inability to pump and circulate adequate amounts of blood through your body in order to meet its needs.
Being Dehydrated
Dehydration is a condition that occurs when your body loses more water than it takes in, the Mayo Clinic says. This can result in fatigue, weakness and dizziness--all of which can be caused by vomiting, severe diarrhea and strenuous forms of exercise. This all ties in to your blood pressure when a complication of dehydration, known as hypovolemic shock, sets in. This is a complication of dehydration and is life-threatening. It takes place when blood volume decreases, resulting in a decrease in blood pressure. This results in a decreased amount of oxygen being transported to your tissues. Death can occur within minutes or hours if not treated, due to the hypovolemic shock.
Severe Infection
Also referred to as septic shock or septicemia, this occurs when an infection invades your bloodstream. The most common cause is bacteria that leave the original infection, such as one that begins in the lungs urinary tract or abdomen. Once leaving any of these sites and entering the bloodstream, toxins from this bacteria infect the blood vessels. This lowers blood pressure to a life-threatening life level, the AHA says.
Medications
People taking certain medications may suffer from hypotension (low blood pressure) as well. These include people taking diruetics to remove excess water from their body, heart medications such as beta-blockers, those who are taking tricyclic antidepressants and people on medication for Parkinson's disease. The AHA says those who are already taking medication for high blood pressure may experience a dip in their blood pressure if they take certain over-the-counter drugs in combination with these prescription medications. For this reason, always check with your doctor before beginning any new drug or supplement.
