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Zana Carver from Thyroid Code wrote the below guest post.
Fluid retention is something I’m asked quite frequently about and can be concerning to live with.
Written by Zana A. Carver, Ph.D.
Have you ever seen the movie, Shallow Hal? It’s a movie in which a man thinks about
women superficially, and introduces the term ‘cankles’. This is a term that refers to swollen ankles, to the point where the calf becomes the ankle, and there’s really nothing to separate the calf from the foot.
Well let me tell you, there is no better description of the swelling that can happen with low thyroid levels!
Have you ever looked at your face in the mirror, hands, or ankles and wondered how their appearance can change so drastically? I’ll be the first to admit that my ankles are not my best feature, but thick ankles served me well in sports. Cankles, however, are not helpful.
Do you feel swollen and puffy? Would you love to wear something special from your closet or even just your wedding ring?
The thyroid gland controls how fast your systems work by releasing thyroid hormones. When thyroid hormone levels are high, the use of nutrients and oxygen to make energy and heat is increased. All body systems and tissues increase their activity in response to thyroid hormones, but when thyroid hormones are low, all tissues slow down. The liver slows down, the heart slows down, circulation slows and so do the kidneys .
Low levels of thyroid hormone (hypothyroidism) can cause tissue swelling in four ways.
1. By slowing down the glomerular filtration rate, which reduces fluid loss through urination
2. By slowing the enzymes that break down mucopolysaccharides (molecules made up of protein and sugar) that are deposited under the skin
3. By causing an overall decrease in circulation, mainly by lowering cardiac output and heart rate but also by affecting the health of blood vessels and often blood pressure
4. By causing fatigue, which can reduce activity levels
There are two types of tissue swelling, also known as edema: pitting and non-pitting (2).
Pitting is where fluid accumulates outside of blood vessels in the space that surrounds cells, the interstitial space. Pitting edema is where an indentation made by pressing a finger on the area remains for minutes to hours afterward. This type of swelling is common with many conditions and is not specific to a thyroid problem. However, it can be increased by low thyroid levels that affect circulation, the kidneys and activity levels.
Non-pitting edema is where sticky molecules called mucopolysaccharides to hold on to water, essentially acting like a sponge . This type of swelling does not cause a visible indentation on the skin when pressed with a finger. When non-pitting edema is severe and caused by hypothyroidism, it’s called myxoedema. Myxoedema is a commonly confused word because it historically was used as a term for severe hypothyroidism but now is mainly reserved for the severe form of swelling caused by hypothyroidism. Myxoedema is most commonly seen in the face, neck, upper arms, and ankles . Myxoedema can specifically indicate a thyroid problem .
I am not unique regarding tissue swelling, but after losing my thyroid to cancer, I have to rely on thyroid hormone replacement. This means that I have to be especially vigilant to the clues of high or low thyroid hormone levels. It’s difficult to know whether I’m cold and tired from other factors, but my face and ankles do not lie.
One of the easiest visual ways to tell if my medication is dosed too low is by looking for signs of swelling, as these changes tend to happen quickly. Edema is especially apparent around the eyes, jawline, fingers, and yes, ankles.
If you’ve noticed swelling around your eyes and hands or the sudden appearance of cankles, please ask your doctor to check your thyroid levels. Even if you are on thyroid medication, your levels can fluctuate.
It is also entirely possible that the type of thyroid medication you are on is not optimal for you. Be your own advocate and record your symptoms to better help your doctor determine the source of your swelling, which may not be a simple reaction to salt.
Do you experience fluid retention?
By Zana A. Carver, Ph.D.
 Braverman and Cooper (2013). Werner & Ingbar’s The Thyroid, A Fundamental and Clinical Text,
10 th ed. Philadelphia, Wolters Kluwer/Lippincott Williams & Wilkins.
 Recognizing the symptoms of myxedema https://www.healthline.com/health/myxedema
 Myxedema Coma: A New Look into an Old Crisis
Dr. Zana Carver is a college professor who specialises in teaching Human Anatomy and Physiology. She has research experience in exposure science and pharmacokinetics (how chemicals move within the body). Pertinently, she also happens to be a thyroid cancer survivor who has had no choice but to learn about all the ways in which thyroid hormone replacement can never truly replace the natural hormonal balance and regulation.
Zana has been disappointed with the long time it takes for good research to be translated into medical “standards of care.” It is, therefore, her mission to find the most helpful and relevant research. It is also Dr. Carver’s mission to translate and contextualise this research for students, thyroid patients, and the general public. You can find her work on her website, Facebook, Instagram and Twitter and also in her book.
If you would like to submit a guest post, whether you’re a thyroid patient, doctor or anyone else, please get in contact.
You can click on the hyperlinks in the above post to learn more and see references to information given.
KristenDecember 6, 2021 at 1:36 am
Interestingly enough Myxoedema is what’s used on UK forms to describe the need for medication for hypothyroidism. Its what i had to tick to get the medical certificate for free prescriptions.
Linda KimmettJune 22, 2019 at 2:54 pm
I have had swollen legs and ankles for years now and am on Thyroid medication. I have tons of other symptoms indicating that my Thyroid is not working. My bloodwork was very high last time and thought the Dr. would increase my meds but he wanted to have it redone in 6 weeks and then it was very low???? My ankles prevent me from doing things in the summer that I would like to do. I have to wear long pants year round and am uncomfortable. Is there anything you can do to help with edema?