Total Cholesterol 398 mg/dL: Is That High?

Is Total Cholesterol 398 mg/dL Low, Normal, or High?

Total cholesterol 398 mg/dL is very high and significantly above the levels considered safe by all major health organizations. The American Heart Association and the National Heart, Lung, and Blood Institute classify total cholesterol of 240 mg/dL and above as high. At 398 mg/dL, your reading is 110 points above that threshold and 150 points above the desirable level of under 200 mg/dL. This is a level that requires prompt medical evaluation and, in most cases, treatment that includes medication alongside aggressive lifestyle changes. A reading this high should not be ignored or postponed, but it is also important to know that effective treatments exist and many people successfully bring very high cholesterol under control.

A total cholesterol reading of 398 mg/dL signifies an exceptionally high and critical level, indicating a profound elevation well beyond the normal range of 150-199 mg/dL. This value is roughly double the upper limit of what is considered healthy, placing an individual at significantly increased and immediate risk for serious cardiovascular events like heart attack or stroke. At such an extreme elevation, common likely causes include a strong genetic predisposition, often suggestive of Familial Hypercholesterolemia (FH), where the body is unable to properly remove LDL cholesterol efficiently. While lifestyle factors undoubtedly play a role, a value this high often points to an underlying primary condition that requires urgent attention. Immediately following such a result, a doctor will typically order a complete lipid panel to assess individual LDL, HDL, and triglyceride levels, and may investigate for secondary causes like hypothyroidism or kidney disease. Referral to a lipid specialist is often warranted. Furthermore, it's worth knowing that if FH is diagnosed, early screening of close family members becomes crucial, as this genetic condition affects relatives directly and can allow for preventative interventions for them too, transforming a concerning diagnosis into a potential opportunity for broader family health. Aggressive therapeutic strategies, including high-dose statins and significant dietary changes, are typically initiated without delay to bring down this dangerous 398 mg/dL value.

Hidden Risk of Total Cholesterol 398 mg/dL

At a total cholesterol of 398 mg/dL, the risks are substantial and well-documented. What makes this level particularly concerning is the speed and intensity with which arterial damage can progress. The American College of Cardiology emphasizes that very high cholesterol levels create a high cumulative cholesterol burden that accelerates cardiovascular disease.

A total cholesterol level of 398 mg/dL significantly elevates your risk for atherosclerotic cardiovascular disease. This extremely high level promotes rapid plaque buildup within arteries, a process known as atherosclerosis. The excess cholesterol, particularly LDL cholesterol which often drives such high total values, infiltrates the artery walls, triggering inflammation and the formation of fatty streaks that progressively harden into atherosclerotic plaques. These plaques narrow the arterial lumen, restricting blood flow and increasing the likelihood of plaque rupture, which can lead to acute events like heart attack or stroke. Furthermore, this level is strongly associated with increased risk of peripheral artery disease, impairing circulation to the limbs.

• At 398 mg/dL, the rate of plaque buildup in your arteries is significantly faster than at borderline levels. Years of damage can be compressed into a shorter timeframe
• Very high cholesterol raises the risk of coronary artery disease, heart attack, and ischemic stroke. The risk is not just elevated, it is multiplied when combined with other factors like high blood pressure, diabetes, or smoking
• Peripheral artery disease, which causes reduced blood flow to the legs, is more common in people with sustained very high cholesterol. Symptoms include leg pain or cramping during walking
• At this level, there is a reasonable chance that a genetic component is involved. Familial hypercholesterolemia affects about 1 in 250 people and can push total cholesterol well above 300 mg/dL from a young age
• People with very high cholesterol sometimes develop visible signs such as xanthomas (yellowish deposits under the skin, often around the eyes, elbows, or tendons) or arcus senilis (a white ring around the iris)
• The danger of very high cholesterol is that arterial plaque can build up silently for years. Many people learn about blockages only when they experience a cardiac event

What Does a Total Cholesterol Level of 398 mg/dL Mean?

Total cholesterol is a combined measurement calculated from the different fats in your blood. The formula is: total cholesterol equals LDL cholesterol plus HDL cholesterol plus 20 percent of your triglycerides. At 398 mg/dL, one or more of these components is dramatically elevated, and understanding the breakdown is critical for guiding treatment.

A total cholesterol reading of 398 mg/dL suggests a severe dyslipidemia, often driven by a combination of factors. A predominantly genetic predisposition, such as familial hypercholesterolemia, is highly probable, where the body has a significantly impaired ability to clear LDL cholesterol. This genetic component is frequently exacerbated by lifestyle choices, including a diet consistently high in saturated and trans fats, coupled with a sedentary lifestyle that limits cholesterol metabolism. Certain medications or underlying medical conditions like uncontrolled diabetes or hypothyroidism can also contribute, though a value this high often points to a primary genetic defect alongside secondary lifestyle influences.

LDL cholesterol is likely the biggest contributor at this level. LDL particles carry cholesterol through your bloodstream, and in excess, they penetrate the walls of your arteries. Once inside, they trigger an inflammatory response that leads to plaque. Plaque is a mixture of cholesterol, fat, calcium, and other substances that builds up over time, narrowing the artery and making it stiff. When a plaque ruptures, it can form a blood clot that completely blocks the artery, which is the mechanism behind most heart attacks and many strokes.

HDL cholesterol is the protective type that transports excess cholesterol back to the liver. Even if your HDL is normal, it may not be able to keep up with the sheer volume of LDL circulating at this level. Triglycerides, the third component, reflect fats your body stores from food. High triglycerides contribute to artery damage and are often elevated alongside high LDL.

A total cholesterol of 398 mg/dL suggests that your body is producing and circulating far more cholesterol than it can safely manage. This could be driven by genetics (familial hypercholesterolemia is a strong possibility at this level), diet and lifestyle factors, underlying medical conditions like hypothyroidism or kidney disease, or a combination of these. Your doctor will order a full lipid panel and likely additional tests to determine the root cause and build a targeted treatment plan.

Lifestyle Changes for Total Cholesterol 398 mg/dL

At 398 mg/dL, lifestyle changes alone are unlikely to bring your cholesterol into the desirable range. However, they are an essential part of a comprehensive treatment plan and significantly boost the effectiveness of medication. The American Heart Association recommends at least 150 minutes of moderate-intensity aerobic exercise per week, and at this cholesterol level, meeting or exceeding that target matters a great deal. Brisk walking, swimming, cycling, and similar activities improve your lipid profile by lowering LDL, raising HDL, and reducing triglycerides. Exercise also improves blood vessel function and reduces inflammation, both of which are critical when cholesterol is very high.

A total cholesterol of 398 mg/dL requires immediate and comprehensive medical management. Schedule an urgent appointment with your primary care physician to initiate further investigation. This will likely include a lipid panel fractionation to specifically identify the LDL, HDL, and triglyceride levels, providing a clearer picture of the lipid profile. You should also begin implementing strict dietary changes, focusing on drastically reducing saturated and trans fats, and increasing soluble fiber intake. Discuss potential medication options, such as statins, with your doctor, as pharmacotherapy is often essential for achieving target levels at this severity. Regular exercise, at least 150 minutes of moderate-intensity activity per week, should be prioritized.

Weight management directly affects cholesterol levels. If you are carrying excess weight, especially around the midsection, losing even a modest amount can make a meaningful difference. The NIH reports that 5 to 10 percent body weight loss can lower LDL by 5 to 8 percent and improve overall cardiovascular markers. At 398 mg/dL, every percentage point of improvement counts.

If you smoke, quitting is not optional at this level. Smoking damages the artery lining, making it far easier for LDL to penetrate and form plaque. It also suppresses HDL, reducing your body's natural defense against cholesterol buildup. The combination of very high cholesterol and smoking creates a dangerously compounded risk. Talk to your doctor about cessation support if you need it.

Sleep and stress management continue to play supporting roles. Chronic sleep deprivation disrupts lipid metabolism, and sustained stress elevates cortisol, which can worsen your lipid profile. Prioritizing seven to nine hours of sleep and finding effective ways to manage stress will not fix the problem on their own, but they support every other intervention you are putting in place.

Written by

Ernestas K.

Clinical research writer specializing in human health, biology, and preventive medicine.

Reviewed against AHA, NIH, ACC, Mayo Clinic, PubMed guidelines · Last reviewed March 20, 2026