Blood pressure (BP) is the pressure of circulating blood on the walls of blood vessels. When used without further specification, “blood pressure” usually refers to the pressure in large arteries of the systemic circulation. Blood pressure is usually expressed in terms of the systolic pressure (maximum during one heart beat) over diastolic pressure (minimum in between two heart beats) and is measured in millimeters of mercury (mmHg), above the surrounding atmospheric pressure (considered to be zero for convenience).
For a normal reading, your blood pressure needs to show a top number that’s between 90 and 120, and a bottom number that’s between 60 and 80. When both your systolic and diastolic numbers are in these ranges, that is the normal range for blood pressure.
Blood pressure is influenced by cardiac output, total peripheral resistance, and arterial stiffness and varies depending on the situation, emotional state, activity, and relative health/disease states. In the short term, it is regulated by baroreceptors which act via the brain to influence nervous and endocrine systems.
There are two types of blood pressures we can see in the human body
- Hypertension or high blood pressure
- Hypotension or low blood pressure
Hypotension is low blood pressure, especially in the arteries of the systemic circulation. A systolic blood pressure of less than 90 millimeters of mercury (mm Hg) or diastolic of less than 60 mm Hg is generally considered to be hypotension. Hypotension or low blood pressure would seem to be something to strive for. However, for many people, low blood pressure can cause symptoms of dizziness and fainting. In severe cases, low blood pressure can be life-threatening. The causes of low blood pressure can range from dehydration to serious medical or surgical disorders. Low blood pressure is treatable, but it’s important to find out what’s causing your condition so that it can be properly treated.
Signs and symptoms regarding Hypotension
- The primary symptoms of hypotension are lightheadedness or dizziness. If the pressures is too low fatigue may occur.
- chest pain
- shortness of breath
- irregular heartbeat
- fever higher than 38.3 °C (101 °F)
- stiff neck
- severe upper back pain
- cough with sputum
- Prolonged diarrhea or vomiting
- dyspepsia (indigestion)
- dysuria (painful urination)
- adverse effect of medications
- acute, life-threatening allergic reaction
- loss of consciousness
- profound fatigue
- temporary blurring or loss of vision
- Black tarry stools
- Low blood pressure can be caused by low blood volume,
- hormonal changes,
- widening of blood vessels,
- medicine side effects,
- heart problems or endocrine problems
- Chronic use of alpha blockers or beta blockers can lead to hypo tension
- Decreased cardiac output
- Under active thyroid
- depression or Parkinson’s disease
- Heart failure
- Heart arrhythmias
- Liver disease
Causes a Sudden Drop in Blood Pressure
- Bleeding of blood
- Low or high body temperature
- Heart muscle disease causing heart failure
- Sepsis, a severe blood infection
- Severe dehydration from vomiting, diarrhea, or fever
- A reaction to medication or alcohol
- Anaphylaxis that causes an irregular heartbeat
- Hypo tension diagnosed first by obtaining a blood pressure. If Mean Arterial Pressure is <65mmHg, this is generally considered hypotension.
- Evaluation of vasovagal syncope is done with a tilt table test.
- The treatment for hypotension depends on its cause.
- Asymptomatic hypotension in healthy people usually does not require treatment
- Adding electrolytes in diet can relieve symptoms of mild hypotension.
- A small dose of caffeine in morning will be more effective
- Volume resuscitation
- Blood pressure support with a vasopressor
- Ensure adequate tissue perfusion
- Address the underlying problem
The best way to determine if a person will benefit from fluids is by doing a passive leg raise followed by measuring the output from the heart.