Hypothyroidism and high cholesterol can be closely connected. When the thyroid gland doesn’t produce enough thyroid hormone, the body’s normal metabolism can slow, including slower ability to clear cholesterol from the bloodstream.
This can contribute to higher total cholesterol and LDL cholesterol, particularly in people with overt hypothyroidism. However, elevated cholesterol does not automatically mean an underactive thyroid as the cause. Genetics, diet, medications, metabolic conditions, and other health factors can also affect cholesterol levels.
Understanding the connection between thyroid function and cholesterol is useful. Thyroid testing is always appropriate in new patients who present to our office with an elevated cholesterol level. Treating an underlying thyroid disorder will improve an abnormal lipid profile.
My Doctor Gave Me a Statin Drug, Do I Need Thyroid Medicine Instead?
Mainstream medical doctors will mindlessly give the patient a cholesterol lowering drug, usually a statin, whenever the cholesterol level is above the current guidelines. It is not unusual to see patients present to my office taking a cholesterol lowering drug when they actually need thyroid medication. This is commonly missed by primary care doctors and represents one of the errors of mainstream medicine.
How Can Hypothyroidism Cause High Cholesterol?
Hypothyroidism can contribute to high cholesterol because thyroid hormones help regulate metabolism and the body’s lipid processing. When thyroid hormone levels are too low, cholesterol metabolism can change, which may lead to higher total cholesterol and LDL cholesterol.
The American Thyroid Association reports that people with hypothyroidism can have increased cholesterol levels and that treating hypothyroidism with thyroid hormone often lowers cholesterol. The effect tends to be more pronounced in overt hypothyroidism than in milder thyroid dysfunction. (1-2)
This means an unexpectedly high cholesterol result may be one reason to consider whether to evaluate thyroid function as well, particularly when other symptoms or risk factors for hypothyroidism are present.
Can Hypothyroidism Raise LDL Cholesterol?
Yes, hypothyroidism can raise LDL cholesterol, one of the main cholesterol measurements used to assess cardiovascular risk. The relationship is better established in overt hypothyroidism, where thyroid hormone levels are low and TSH is elevated.
Subclinical hypothyroidism is different. In this condition, TSH is elevated while free T4 remains within the reference range. Treating subclinical hypothyroidism produces smaller improvements in cholesterol than treatment of overt hypothyroidism.
Therefore, an elevated LDL level should not automatically be attributed to thyroid disease. A complete evaluation is needed to determine what factors may be contributing.
What Symptoms May Suggest an Underactive Thyroid?
High cholesterol alone does not diagnose hypothyroidism, but it may occur alongside symptoms associated with reduced thyroid function. Possible symptoms include:
- Fatigue or low energy
- Feeling unusually cold
- Unexplained weight changes
- Dry skin
- Constipation
- Hair changes
- Difficulty concentrating
These symptoms are not specific to hypothyroidism and can occur with other conditions. Symptoms should therefore be considered alongside medical history and appropriate laboratory testing, rather than used as a diagnosis on their own.
A person can also have hypothyroidism without obvious symptoms, making laboratory evaluation relevant when thyroid dysfunction is suspected.
Which Thyroid Tests Can Help?
Primary care and endocrinologists will usually run the TSH with reflex to Free T4. If the TSH is out of range, then the lab automatically runs the free T4. This means the Free T4 will not be done unless the TSH is out of range. Having only a TSH value is not enough information to rule out a low thyroid condition. At our TruemedMD Clinic, we do a complete thyroid panel on all new patients which includes TSH, Free T3, Free T4, reverse T3, antithyroid antibodies, H. Pylori breath test, selenium and anti-gliadin antibodies. Note: this is a test for wheat gluten sensitivity.
Laboratory testing is most useful when interpreted in context. A cholesterol panel (also called a lipid panel) can show elevated cholesterol but cannot determines whether a low thyroid condition is present.
Thyroid antibody testing is useful to evaluate autoimmune thyroid conditions such as Hashimoto’s thyroiditis when clinically indicated. We always include anti-thyroid antibodies on the initial lab panel.
Can Treating Hypothyroidism Lower Cholesterol?
Treating overt hypothyroidism can lower total and LDL cholesterol, although the amount of improvement may vary. The American Thyroid Association reports that levothyroxine treatment in overt hypothyroidism significantly reduced total cholesterol and LDL cholesterol in reviewed studies. Levothyroxine is T4 only medication. A more robust and superior treatment is combined T3 and T4 using NDT, natural desiccated thyroid.
The reduction in serum cholesterol is less pronounced in subclinical hypothyroidism. This distinction matters. Treating a low thyroid condition with thyroid medication usually shows some reduction in cholesterol level, but not in all cases. Cholesterol can remain elevated because of other factors, including a genetic abnormality called familial hypercholesterolemia, diabetes, metabolic syndrome, insulin resistance, certain high fat or carnivore diets, lack of physical activity, and other medical conditions. Thyroid treatment alone may not resolve every case of elevated cholesterol level.
What If Cholesterol Stays High After Thyroid Treatment?
If cholesterol remains elevated after thyroid function is normalized with treatment, other factors are contributing to the elevated cholesterol level. Normalizing thyroid function can address one potential contributor, but it does not eliminate other causes of elevated serum cholesterol.
Research reviewed by the American Thyroid Association has found that some people treated with levothyroxine and achieving normal TSH levels can still have higher cholesterol levels than healthy individuals. (1-2)
This is why careful follow-up labs are useful which include lipid profile, thyroid panel. Follow up also includes a review of symptoms, current medications, medical history, lifestyle factors, etc.
When Should You Check Your Thyroid If You Have High Cholesterol?
Consider discussing thyroid testing with a healthcare professional if you have unexplained high cholesterol, symptoms suggestive of hypothyroidism, or other reasons to suspect a thyroid disorder. At our TruemdMD clinic, we do a complete thyroid panel on all new patients, so this is routinely included. Additional testing is based on your clinical history, individual symptoms, and follow up laboratory studies.
Thyroid treatment begins with a a complete medical evaluation including review of symptoms, medical history, physical examination, and laboratory findings. All this information is integrated together to decide on an individualized treatment plan which usually includes NDT, natural desiccated thyroid and supportive supplements.
Can Your Thyroid Be the Reason for High Cholesterol?
Understanding the link between hypothyroidism and high cholesterol can help identify whether an underactive thyroid is contributing to an elevated cholesterol level.
If you are concerned about your thyroid or cholesterol levels, our medical director, Jeffrey Dach MD provides a full thyroid evaluation, laboratory diagnostic testing, and thyroid treatment based on your clinical history, symptoms, and laboratory results.
Frequently Asked Questions
Can hypothyroidism cause high cholesterol?
Yes. Hypothyroidism can increase total cholesterol and LDL cholesterol because thyroid hormones influence cholesterol metabolism. The effect is generally more pronounced in overt hypothyroidism than in subclinical hypothyroidism.
Why does hypothyroidism raise LDL cholesterol?
Low thyroid hormone levels can alter the body’s normal processing and clearance of cholesterol. As a result, LDL and total cholesterol serum levels may increase in people with hypothyroidism.
Can treating hypothyroidism lower cholesterol?
Yes, treating overt hypothyroidism can lower total and LDL cholesterol serum levels. However, serum cholesterol may remain elevated when other contributing factors are present, such as familial hypercholesterolemia, a genetic disorder.
Should I have my thyroid checked if my cholesterol is high?
Yes, this is a good idea. Thyroid testing may be appropriate when cholesterol is elevated without an obvious explanation or when symptoms or medical history suggest thyroid dysfunction. A healthcare professional can determine which tests are appropriate for your situation.
My Doctor Gave me a Statin Drug for High Cholesterol. Should I have my Thyroid Checked?
It is not unusual to see a new patient in my office on a statin drug for elevated cholesterol, while the real problem is underlying hypothyroidism, i.e. a low thyroid condition. This is why we do an extensive thyroid panel on all new patients, so we do not miss this diagnosis. These patients do not need a statin drug which will only make them feel worse. Instead, they need thyroid medication, preferably natural desiccated thyroid (NDT) which contains both T3 and T4 which will promptly bring down the cholesterol level and give them full relief of hypothyroid symptoms, with increased energy and improved cognitive function. Here at the TruemedMD clinic, our medical director, Jeffrey Dach MD does a complete evaluation to find underlying causes, and then comes up with a well thought out treatment plan. After the patient is started on treatment, we use careful follow up to monitor the response. If you are interested in a higher level of medical care, Contact our office today.
Articles with Related Interest:
The Failure of Cholesterol Lowering Drugs
Does Cholesterol Cause Coronary Artery Disease?
The Art of the Curb Side Cholesterol Consult
Cholesterol Lowering Statin Drugs for Women, Just Say No to Statin Drugs
Familial Hypercholesterolemia and Statin Drugs
References:
- Kotwal, Anupam, et al. “Treatment of Thyroid Dysfunction and Serum Lipids: A Systematic Review and Meta-analysis.” The Journal of Clinical Endocrinology & Metabolism, vol. 105, no. 12, 2020, dgaa672.
- American Thyroid Association. “Treating Hypothyroidism Decreases Cholesterol Levels.” Clinical Thyroidology for the Public, vol. 14, no. 4, Apr. 2021, pp. 6-7.
