SNP Shot: Genomic Insights

Hypertension, also known as high blood pressure, occurs when the pressure in your arteries is consistently too high. Arteries are the blood vessels that transport blood from your heart to the rest of your body. Each heartbeat forces blood through these arteries, delivering vital nutrients and oxygen. Blood pressure is the force of this blood against the artery walls, measured in millimeters of mercury (mmHg). A blood pressure reading has two numbers: the top number (systolic) reflects the pressure when the heart beats, and the bottom number (diastolic) represents the pressure between beats. A normal blood pressure for adults is typically around 120/80 mmHg. A reading of 130/80 mmHg or higher is considered hypertension.

Often, hypertension has no noticeable symptoms, so many people are unaware they have it. However, it significantly increases the risk of serious health problems, including heart disease, stroke, kidney failure, and eye damage. Elevated blood pressure forces the heart and arteries to work harder. This extra work can thicken the heart muscle and artery walls, and damage or harden the arteries. Consequently, blood and oxygen flow to the heart and other organs is reduced. This can lead to heart disease. Furthermore, damaged arteries are more prone to blood clots, which can block blood flow to the heart (causing a heart attack) or to the brain (causing an ischemic stroke). A hemorrhagic stroke can occur when a weakened blood vessel in the brain ruptures. Kidney damage from high blood pressure impairs their ability to filter waste and fluid, potentially causing kidney failure. Additionally, restricted blood flow to the eyes can result in vision loss.

In infrequent instances, severely elevated blood pressure may manifest as intense headaches, confusion, shortness of breath, chest pain, or nosebleeds.

In the majority of cases (around 95%), the cause of hypertension is unknown; this is referred to as essential hypertension. When hypertension is caused by an identifiable underlying condition, such as blood vessel abnormalities that restrict blood flow, kidney problems affecting fluid and salt balance, or issues with hormone-producing glands like the adrenal or thyroid, it's classified as secondary hypertension. Hypertension is also a prominent symptom of certain rare genetic disorders, including familial hyperaldosteronism, pseudohypoaldosteronism type 2, Liddle syndrome, and paragangliomas (tumors).

Inheritance:

Hypertension has a tendency to occur within families. Individuals with parents who have hypertension are at a higher risk of developing the condition themselves, particularly if both parents are affected. However, the specific inheritance pattern is not fully understood. Rare, genetic forms of hypertension follow the inheritance pattern specific to that particular genetic condition.