High LDL and triglycerides increase the risk of atherosclerosis, heart attack, and stroke. Causes include diet (saturated and trans fats), inactivity, smoking, certain illnesses and medications, and genetic disorders. Start with lifestyle changes - healthier fats, more fiber, weight control, and exercise - and work with your clinician on screening and medication when needed.

Why cholesterol matters

Cholesterol is a fat-like substance your body needs to build cells and hormones. Problems arise when too much low-density lipoprotein (LDL, often called "bad" cholesterol) and triglycerides build up in blood vessels. Over time this can narrow arteries and raise the risk of heart attack, stroke, and peripheral artery disease.

Common causes of high cholesterol

Diet and body weight

Eating a lot of saturated fat, trans fats, and excess calories contributes to higher LDL and triglycerides. Eating fewer whole foods and more processed items makes it hard to maintain a healthy weight - and excess weight itself raises cholesterol.

Physical inactivity and smoking

Too little physical activity lowers HDL (the "good" cholesterol) and raises triglycerides. Smoking damages blood vessels and worsens cholesterol-related risk.

Age, sex, and hormones

Cholesterol levels change with age and with hormonal status. For example, after menopause, many women see higher LDL levels.

Medical conditions and medications

Certain conditions - such as diabetes, hypothyroidism, chronic kidney disease, and some liver disorders - can raise cholesterol. Some medicines (for example, certain corticosteroids or antiretroviral drugs) can also affect lipid levels.

Genetics

Familial hypercholesterolemia and other inherited lipid disorders can cause very high LDL levels at a young age. A family history of early heart disease is a strong signal to check lipids sooner.

What the risks look like

High LDL and triglycerides contribute to atherosclerosis: fatty deposits that stiffen and narrow arteries. That process increases the chance of heart attack and stroke. Risk accumulates over years, so early detection and treatment matter.

How to lower cholesterol

Lifestyle changes (first line for many people)

  • Choose unsaturated fats (olive, canola, nuts) over saturated and trans fats.
  • Eat more fiber: whole grains, legumes, fruits, and vegetables help lower LDL.
  • Aim for regular physical activity (for most adults, about 150 minutes of moderate activity per week or as advised by a clinician).
  • Maintain a healthy weight and stop smoking.
  • Limit excess alcohol.

Medicines and clinical care

If lifestyle changes aren't enough, clinicians commonly use statins as first-line drug therapy to lower LDL. Other medications (for example, ezetimibe or PCSK9 inhibitors) may be appropriate for people at higher risk or those with genetic disorders. Your clinician will consider your overall cardiovascular risk when recommending treatment.

Screening and follow-up

How often you get checked depends on your age, health, and family history. Many clinicians recommend periodic lipid checks and more frequent monitoring if you have known high cholesterol, cardiovascular disease, or a strong family history.

Takeaway

High cholesterol often develops from a mix of diet, lifestyle, health conditions, and genetics. You can reduce long-term risk by getting screened, improving diet and activity, and following a clinician's plan - which may include medication - tailored to your risk.

FAQs about Causes Of High Cholesterol

How do I know if I have high cholesterol?
Only a blood test (lipid panel) can measure LDL, HDL, and triglycerides. Talk to your clinician about when to test based on age, health, and family history.
Can diet alone fix high cholesterol?
Lifestyle changes can significantly lower cholesterol for many people, but some need medicines - especially those with very high LDL, established cardiovascular disease, or certain genetic conditions.
What role do statins play?
Statins are commonly used first-line medicines to lower LDL and reduce cardiovascular risk. Your clinician will decide if they're appropriate based on your overall risk profile.
Should I worry if high cholesterol runs in my family?
Yes. A family history of early heart disease or very high cholesterol suggests possible inherited risk and warrants earlier testing and specialist input.
What lifestyle changes make the biggest difference?
Replacing saturated/trans fats with unsaturated fats, increasing fiber-rich foods, losing excess weight, being physically active, and quitting smoking have the largest impact.