High blood fats (cholesterol)
High blood fats have no symptoms and only a test shows them. Here you can read what the test numbers mean, how often they should be checked, and how blood fats are linked to blood sugar, blood pressure, the thyroid and fatty liver.
What are high blood fats?
Cholesterol is a waxy, fat-like substance that the liver makes, and the body needs a suitable amount of it to make hormones and digest fats. The problem comes when the amount is too high. Blood fats have several parts:
- LDL (“bad cholesterol”): When it is high, it builds up as plaque in the walls of the vessels and raises the risk of heart problems and stroke.
- HDL (“good cholesterol”): It carries cholesterol back to the liver so that it leaves the body. A higher HDL is helpful.
- Triglycerides: A fat the body uses for energy. High triglycerides together with low HDL or high LDL raise the risk of heart attack and stroke.
Plaques narrow the vessel and can reduce blood flow to the heart and other organs. Reduced blood flow to the heart can lead to chest pain (angina) or a heart attack.
Symptoms
High blood fats usually have no symptoms at all. The only way to find out is a blood test. If plaque blocks blood flow to the heart, chest pain or a heart attack follows, but until then nothing is felt (see the section “When to get help”).
Blood fats and the rest of the body
Blood fat numbers have no meaning apart from the rest of the body:
- Blood sugar: Type 2 diabetes is a risk factor for high blood fats. Someone with diabetes should follow their blood fats too.
- Blood pressure: High blood pressure and high blood fats both damage the vessels, and together they raise the risk further. That is why someone with high blood pressure has their blood fats tested earlier or more often.
- Thyroid: An underactive thyroid can contribute to high blood fats, and it is recommended that someone with high blood fats also have a thyroid test.
- Liver: Someone with fatty liver is more exposed to heart and vessel disease, type 2 diabetes and “metabolic syndrome”, and abnormal blood fats (cholesterol and triglycerides) are part of that same group.
- Weight, food and activity: A high-fat diet (especially saturated and trans fat), inactivity and excess weight raise blood fats. Family history and genes also play an important part.
How is it diagnosed?
With a blood test called a lipid profile or lipid panel. This test measures total cholesterol, LDL, HDL and triglycerides. You may need to avoid eating and drinking for 9 to 12 hours beforehand.
The numbers these sources give for adults (mg/dL):
| Measure | Number |
|---|---|
| Total cholesterol | Less than 200 is normal (one reference counts about 150 as ideal and above 200 as high) |
| LDL | Less than 100 |
| HDL | Best 60 or more; below 40 in men and below 50 in women is low |
| Triglycerides | Less than 150 |
| non-HDL | Less than 130 |
None of these numbers is your personal target. The right target depends on age, family history, diabetes, blood pressure, smoking and other factors, and your doctor will set it.
How often should it be checked?
References do not give one schedule, and one of them says to ask your care team. One reference suggests this: adults 20 to 65 every 5 years, men 45 to 65 and women 55 to 65 every 1 to 2 years, and over 65 every year. People with risk factors, such as a family history of heart disease, high blood pressure, type 2 diabetes, smoking, excess weight or inactivity, are tested earlier or more often. Your schedule will be set by your doctor.
Treatment and management
The aim is to bring blood fats into a healthy range, with lifestyle change or medicine or both:
- Food: Less saturated and trans fat. Reduce, as far as possible, the cholesterol in animal foods (meat, chicken, eggs, dairy). More vegetables, fruit, whole grains and pulses.
- Activity and weight: Regular physical activity and reaching a healthy weight.
- Tobacco: Stop smoking.
- Medicine: Some people need medicine as well as lifestyle change. Whether you need medicine is decided by the doctor based on your numbers and your overall risk factors. Do not start, stop or change a medicine yourself.
Follow-up and self-care
- Repeat the blood fat test according to your doctor’s plan and keep the results so you can see the trend.
- If anyone in the family has had high blood fats, a heart attack or a stroke at a young age, tell your doctor. High blood fats are sometimes inherited and start at a young age.
- Follow your blood sugar, blood pressure and thyroid too, as your doctor advises.
- Tell your doctor about every medicine, supplement and herbal remedy you take.
When to get help
High blood fats are not an emergency in themselves, but their complications are. Call 115 (Iran’s emergency number) immediately if you have sudden pain or pressure in the chest that does not go away, spreads to the arm, neck, jaw, abdomen or back, or comes with sweating, nausea, light-headedness or shortness of breath. Sudden weakness or numbness, a change in vision and trouble speaking are also emergencies. Do not drive yourself.
If your test numbers are high, if you have a family history of early high blood fats or heart disease, or if you do not know when your blood fats were last checked, book an appointment and talk to your doctor.
Every patient’s treatment plan is different. Ask your doctor about your own situation.
Frequently asked questions
My blood fats are high but I feel healthy. Is it serious?
Yes. The fact that there are no symptoms is exactly what hides it. High blood fats can be silent for years, narrowing the vessels and raising the risk of heart problems and stroke. The only way to find out is a blood test. How worried to be and what to do depends on your numbers and your other risk factors, and the doctor decides.
What are the right numbers for LDL and total cholesterol?
Sources do not give one identical number. One reference counts total cholesterol below 200 mg/dL as normal, and another counts about 150 as ideal and above 200 as high. For LDL, both say about 100 mg/dL or less. The right number for you depends on age, family history, diabetes, blood pressure and lifestyle, and your doctor will set it.
Do I need to fast for the blood fat test?
Sometimes. You may be asked not to eat or drink for 9 to 12 hours, which is why the test is usually taken in the morning. The laboratory or the doctor will tell you whether fasting is needed.
If my blood fats come down, should I stop the medicine?
Not without the doctor. If you take medicine and the number has improved, it is probably the result of that same treatment. The decision about medicine is made only by the doctor, based on your tests and overall situation.
Why does the doctor ask for a thyroid test when blood fats are high?
An underactive thyroid can contribute to raised blood fats. That is why a thyroid test is also recommended for someone with high blood fats.