Low Blood Pressure (Hypotension) Causes

Low blood pressure can be temporary, or it can be a chronic (long-lasting) condition.

These are the following medical reasons that may lead to low blood pressure:

• Blood loss: Losing a lot of blood, such as from a major injury or internal bleeding, reduces the amount of blood in your body, leading to a severe drop in blood pressure.
• Septicemia (Infection): A recognized cause of low blood pressure is shock arising from severe infection and resulting from the infection entering the bloodstream.
• Severe dehydration from vomiting, diarrhea, or fever may lower blood pressure.
• Heart conditions such as heart attacks or abnormal heartbeats may render the heart incapable of supplying more constant blood flow and may cause low blood pressure.
• Hormonal imbalance: An imbalance in its production of hormones can cause a drop in blood pressure. Thyroid conditions and low blood sugars are often cited as causes of low blood pressure. Adrenal gland imbalance can also cause low blood pressure.
• Chronic kidney disease: Patients suffering from kidney failure are known to have episodes of low blood pressure, especially during dialysis or when they stand or sit up suddenly. This may be due to damage to the nerves that control the blood pressure.
• Anaphylaxis: A severe reaction to an allergen can also cause symptoms of low blood pressure by causing the heart to beat irregularly and impeding the flow of blood.
• Pregnancy: Fluctuations in blood pressure during pregnancies are seen as the body adapts itself to host the baby, and there are changes in the hormonal levels.
• Medication side effects: Some medicines for heart conditions, hypertension, or depression can cause dilation of blood vessels resulting in a sudden drop in blood pressure. More often, the lowered pressure is a mild side effect of the medication and not much cause for concern, for example, blood pressure medicines, medicines for erectile dysfunctions, and drugs for many mental health disorders.
• Heat exhaustion or heat stroke: It is one of the common causes of dehydration and low blood pressure.

• To have low blood pressure for a short duration is not always a concern as the body will try to bring it to normal.
• However, severe hypotension can cause a lack of blood flow to the brain, heart, and kidneys causing further complications.
• Low blood supply to the brain may cause dizziness, blackouts, or loss of consciousness and may even be life-threatening in severe cases. 
• Low blood pressure or hypotension is a condition where the systolic and diastolic pressure falls below 90 and 60 (mm Hg), respectively. Normal blood pressure is 120/80 mm Hg. Systolic pressure is the pressure exerted on the arteries by a column of blood. Diastolic pressure is the pressure in the arteries when the heart rests between beats.
• Usually, low blood pressure is a sign or symptom of underlying medical condition or aging-related conditions. It is necessary to pay attention to signs and symptoms of low blood pressure in its initial stages.

Symptoms of low blood pressure include:

• Lightheadedness or dizziness
• Nausea/vomiting
• Tiredness or weakness
• Cold sweaty skin
• Palpitations
• Shallow and rapid breathing
• Confusion or mental fog
• Loss of consciousness
• Weak pulse
• Fever (infective cause of low blood pressure)
• Pale skin
• Convulsions (in reduced blood supply to brain)

Low blood pressure can be treated and does not require much medication unless accompanied by other conditions. Often, lifestyle and diet modifications may become necessary. Common recommendations include:

• Increase intake of water 
• Increase sodium in diet (to be done with medical advice only)
• Treat the underlying causes
• Lifestyle modifications: Regular exercises keeping the body fit increase the pumping capacity of the heart and reduce the symptoms of low blood pressure. Reducing alcohol intake also helps.
• If certain medication causes low blood pressure, doctors may recommend a substitute or even stopping its consumption.
• Compression stockings to prevent pooling of blood at the limbs are suggested. 

In cases of more severe or recurrent symptoms of low blood pressure, doctors may prescribe drugs to stabilize the system. These may include:

• Fludrocortisone: It is a steroid that is prescribed when the body is unable to produce enough by itself and is often prescribed in conjunction with other steroids such as hydrocortisone. It reduces inflammation in the body and causes the body to retain more sodium. It may cause some water retention, but this is not a cause for concern because it is necessary to build blood pressure. 
• Midodrine: It is a vasopressor that constricts small blood vessels to increase blood pressure. The dosage is gradually increased over time to prevent side effects.