What is high cholesterol?
Let’s say your bloodstream is like a busy highway. Now imagine cholesterol as the trucks delivering essential building materials—great in moderation, but chaos if there are too many.
High cholesterol means you have too much of a fatty substance called cholesterol in your blood. This condition doesn’t cause symptoms by itself, which is why it’s often called a “silent threat.” But over time, it can clog your arteries and lead to serious problems like heart attacks or strokes.
Globally, high cholesterol is one of the major risk factors for cardiovascular disease (CVD), which accounts for nearly one-third of all deaths worldwide each year, according to the World Health Organization (WHO).
How does high cholesterol occur?
So, how does something so essential to your body become dangerous?
Cholesterol is made by your liver and also comes from the food you eat, particularly animal-based products like meat, eggs, and dairy. Your body uses it to build cells and hormones. But problems start when there’s too much “bad” cholesterol.
Here’s an analogy: imagine pouring grease down your kitchen sink every day. Eventually, it builds up, narrowing the pipes. That’s pretty much what low-density lipoprotein (LDL) does—it deposits cholesterol in your arteries, forming plaques. These plaques can eventually rupture and cause a blood clot—leading to heart attacks or strokes.
On the flip side, high-density lipoprotein (HDL) helps clean out the pipes. It carries cholesterol back to the liver, where it’s broken down and removed. A healthy balance between the two is vital.
What are the causes of high cholesterol?
High cholesterol can sneak up on anyone. In many cases, people don’t even know they have it until something serious happens.
The most common causes include:
- Unhealthy diet (over 50% of cases): Especially one high in saturated fats (found in red meat, butter, cheese) and trans fats (found in processed foods).
- Lack of physical activity
- Obesity or being overweight
- Smoking: It lowers HDL (good) cholesterol.
- Genetics (familial hypercholesterolemia): A rare inherited condition that affects 1 in 250 people globally and causes cholesterol levels to skyrocket, even in childhood.
- Medical conditions: Such as diabetes, kidney disease, and hypothyroidism.
- Age and sex: Cholesterol naturally rises as you age, and women’s levels often go up after menopause.
Who is at risk of high cholesterol?
Before you shrug this off, ask yourself—do you know your cholesterol level?
Many people at risk have no clue. A few things can quietly increase your risk over time:
- Poor diet (especially high in saturated and trans fats)
- Sedentary lifestyle
- Being overweight or obese
- Family history of heart disease or high cholesterol
- Age (men over 45 and women over 55 are at greater risk)
- Smoking
- Alcohol overconsumption
- Certain medical conditions, especially type 2 diabetes and hypothyroidism
Interestingly, even thin people can have high cholesterol if their diet is poor or they have a genetic tendency.
What are the symptoms of high cholesterol?
This is the tricky part: high cholesterol doesn’t cause any symptoms. Most people only find out after a heart attack, stroke, or through a blood test.
However, in rare genetic disorders like familial hypercholesterolemia, you might see signs such as:
- Xanthomas: Yellowish bumps under the skin or around the eyes (cholesterol deposits)
- Corneal arcus: A white or gray ring around the colored part of the eye
These are rare and usually only show up in extreme cases. For most people, the only way to know is through a blood test.
What conditions mimic high cholesterol (Differential Diagnosis)?
Since high cholesterol doesn’t cause clear symptoms, it often overlaps with or gets overlooked in favour of other issues. However, it’s essential to distinguish it from:
- Metabolic syndrome: A cluster of conditions including high blood pressure, high blood sugar, and abnormal cholesterol.
- Hypothyroidism: Can lead to elevated LDL cholesterol.
- Nephrotic syndrome: A kidney disorder that also increases lipid levels.
- Diabetes mellitus: Often coexists with dyslipidemia.
- Liver disease: Can alter lipid metabolism and confuse the diagnosis.
A thorough clinical history and blood work help to rule out these conditions and pinpoint cholesterol as the culprit.
How is high cholesterol diagnosed?
The gold standard? A lipid panel or lipid profile test—a simple blood test that measures:
- Total cholesterol
- LDL (bad) cholesterol
- HDL (good) cholesterol
- Triglycerides (another fat that can increase heart risk)
To get the most accurate reading, the test is usually done after 9–12 hours of fasting.
Here’s what the numbers mean (in mmol/L):
- Total cholesterol: Less than 5.0 mmol/L is desirable
- LDL cholesterol: Less than 3.0 mmol/L
- HDL cholesterol: More than 1.0 mmol/L (men), 1.3 mmol/L (women)
- Triglycerides: Less than 1.7 mmol/L
Doctors will interpret your results based on your overall cardiovascular risk, not just the numbers alone.
How do we treat high cholesterol?
Treatment starts with one powerful word: lifestyle.
1. Lifestyle Changes (First-line treatment)
These are often enough to lower cholesterol significantly, especially in borderline cases:
- Eat a heart-healthy diet:
- More fibre (e.g., oats, beans, fruits)
- Less saturated fat and trans fats
- More healthy fats (olive oil, avocado, nuts)
- Exercise: 30 minutes a day, 5 days a week
- Lose weight if overweight
- Quit smoking
- Limit alcohol
2. Medications (When lifestyle changes aren’t enough)
If your cholesterol is very high or you’re at high risk of heart disease, medication is usually needed.
- Statins (e.g., atorvastatin, simvastatin): Reduce LDL by blocking cholesterol production in the liver. This is the gold standard.
- Ezetimibe: Reduces cholesterol absorption in the intestines.
- PCSK9 inhibitors (e.g., evolocumab): Injectable drugs for very high-risk patients.
- Bile acid sequestrants: Help remove cholesterol via the bowel.
- Fibrates and niacin: Mostly used to target triglycerides.
Doctors will tailor the treatment based on your age, risk factors, and how you respond to the initial therapy.
Final Thoughts
High cholesterol is a silent but deadly condition. The good news? It’s highly manageable—and even preventable. You don’t need to wait for a heart attack to take it seriously.
So, when was your last cholesterol test?
References
- World Health Organization – Cardiovascular Diseases (CVDs). https://www.who.int/news-room/fact-sheets/detail/cardiovascular-diseases-(cvds)
- NHS – High cholesterol. https://www.nhs.uk/conditions/high-cholesterol/
- Mayo Clinic – High cholesterol. https://www.mayoclinic.org/diseases-conditions/high-blood-cholesterol/symptoms-causes/syc-20350800
- American Heart Association – Cholesterol. https://www.heart.org/en/health-topics/cholesterol
- National Heart, Lung, and Blood Institute – Cholesterol levels. https://www.nhlbi.nih.gov/health/cholesterol