Also called: Hypothyroid myopathy; thyroid muscle pain; hypothyroidism
Relief and prevention
Strength
Stretch
Massage
Aching, heavy, stiff muscles that no amount of stretching touches - because the muscle is not tight, it is underpowered. Low thyroid hormone slows muscle energy metabolism and slows relaxation, and the symptoms are worse after exertion.
How common: Muscle pain, cramps and stiffness affect about 75% of people with hypothyroidism and some degree of muscle involvement is found in 30-80%; hypothyroidism itself affects roughly 5% of adults, with a similar number undiagnosed
What it is
Thyroid hormone sets the pace of energy metabolism in every cell, and muscle is one of the most metabolically active tissues there is. When it is low, muscle fibres generate energy more slowly, contract and relax more slowly, and recover from exertion poorly.
The distinguishing feature is that this is not a tightness problem. Stretching a muscle that is short helps; stretching one that is underpowered does nothing at all. That is a genuinely useful clue - months of stretching with no change, in someone with fatigue, cold intolerance and weight gain, should raise the question of the thyroid.
What it feels like
- Deep aching and heaviness in the large muscles - thighs, shoulders, calves
- Stiffness and cramping, particularly after exertion
- Muscles that take much longer than expected to recover from a session
- Weakness climbing stairs and getting out of a chair
- Alongside fatigue, cold intolerance, weight gain, dry skin, constipation and low mood
What causes it
Most people have more than one of these at once, and they feed each other. Read the
list looking for the two or three that sound like your week rather than for the one
true answer — the ones that describe you are the ones worth acting on.
- Slowed muscle energy metabolism
- Thyroid hormone regulates mitochondrial function and the rate at which muscle produces energy. Low hormone means less energy available per contraction, which is felt as heaviness and early fatigue.
- Slowed muscle relaxation
- The pumps that return calcium after a contraction work more slowly. Muscle takes longer to release, which produces stiffness, cramping and the characteristically slow-returning reflexes.
- Impaired glycogen and lipid handling
- Muscle cannot use fuel as efficiently, so exertion is harder and recovery from it takes longer. The symptoms are typically worse the day after activity.
- Autoimmune thyroid disease
- Hashimoto's thyroiditis is the commonest cause of hypothyroidism in iodine-sufficient countries. It develops gradually, which is why the symptoms creep up over years.
- Treated thyroid disease that is under-replaced
- Being on levothyroxine does not guarantee the level is right. Muscle symptoms in a treated patient are a reason to re-check the blood tests rather than to assume the thyroid is dealt with.
- Statins alongside hypothyroidism
- Untreated hypothyroidism substantially raises the risk of statin muscle symptoms. Someone with both may be blaming the wrong one, and correcting the thyroid often resolves it.
- Vitamin D deficiency
- Common alongside hypothyroidism and an independent cause of muscle aching. Both are worth checking together, since correcting one and not the other leaves symptoms unexplained.
- Post-thyroid-surgery or radioiodine
- Anyone who has had thyroid surgery or radioiodine treatment needs replacement, and the dose needs periodic review as requirements change.
- Amiodarone and lithium
- Both can cause hypothyroidism. Worth knowing if symptoms appeared after starting either.
Who tends to get it
- Women, in whom hypothyroidism is several times more common
- Anyone with a family history of thyroid or other autoimmune disease
- People already on levothyroxine whose dose has not been reviewed recently
- Anyone with unexplained muscle aching, fatigue, cold intolerance and weight gain together
- People who have had thyroid surgery or radioiodine treatment
What makes it worse, and what settles it
Makes it worse
- Assuming it is a tightness problem and stretching for months
- Hard training before the thyroid level is corrected, which produces disproportionate soreness
- Ignoring it, since untreated hypothyroidism has effects well beyond muscle
- Being on a statin with untreated hypothyroidism, which multiplies the muscle risk
- Assuming that being on levothyroxine means the level must be right
Settles it
- Getting thyroid function tested, which is the entire point of recognising this pattern
- Correcting the hormone level, after which the muscle symptoms usually resolve over weeks to months
- Gentle graded exercise while the level is being corrected rather than hard training
- Massage and heat for symptomatic relief
- Checking vitamin D at the same time, since the two travel together
What actually helps
The short version: Low thyroid hormone slows muscle energy metabolism and slows relaxation. The result is aching, cramping, heaviness and stiffness that is worse after exertion, plus slow-returning reflexes - and no amount of stretching touches it, because the muscle is not tight, it is underpowered
Strength work: Full Body; Legs: Quads; Glutes; Back: Lats; Legs: Calves: Soleus - start well below what you think you can do; strength comes back as the blood levels correct
Stretching: Full Body; Legs: Calves; Legs: Hamstrings; Shoulders; Spine
Massage: Legs; Back; Legs: Calves; Foam Roller Massage - genuinely comfortable, genuinely not the treatment
Also worth doing: Get thyroid function tested. This is the entry whose whole point is a blood test - if diffuse aching arrived alongside cold intolerance, fatigue, weight gain, constipation and dry skin, stretching is not the answer
What the evidence says: Muscle symptoms improve as thyroid replacement takes effect, but slowly - often over months. Training recovers the strength that was lost; treating the thyroid is what fixes the ache. Symptom severity tracks the degree and duration of the deficiency.
The names above are the Targets qFIT tracks —
the Muscle Guide explains what each one does, and
Quick Add switches on the Exercises you
already have.
The qFIT routine for this
Ready-made routineGentle Start (Fatigue & Flare-Ups)
qFIT already has this one built. It runs massage first, then stretching, then
strength — the order that works on a body that is already sore — and every
activity in it carries the reason it is there.
The button below opens your Checklist with this routine already selected, so instead
of your whole list you land on just its Categories, Targets
and Exercises, each with its checkbox, ready to tick as you work through
them.
Have more than one problem? Tick yours under My Problems on
My Profile and your Checklist's Routine list gains
Recommended for my problems — every routine for the problems you picked, merged
into one. Your picks stay private; that filter is the only thing they feed.
Get it checked if…
Rapidly progressive weakness, difficulty swallowing or breathing, severe muscle swelling, or dark urine - hypothyroidism can occasionally cause rhabdomyolysis and that needs urgent care
And whatever the body part: chest pain or unusual breathlessness on
exertion; a fever alongside the pain; unexplained weight loss; pain that is constant and
unrelated to how you move; new numbness, weakness or loss of bladder or bowel control; or
one calf that is swollen, warm and painful. Any of those, stop and get assessed.
How it usually goes
Muscle symptoms usually improve substantially within one to three months of the thyroid level being properly corrected, though it can take longer in severe or long-standing cases. Strength returns more slowly than the aching resolves, and a graded return to training works better than jumping straight back. The value of this page is diagnostic: months of unexplained muscle aching and fatigue that has not responded to anything is a reason to have a blood test rather than a different stretch.
Prevalence basis: Endocrine and neuromuscular reviews of hypothyroid myopathy
Others the same routine covers
These share the Gentle Start (Fatigue & Flare-Ups) routine, so the work is the same. If one of them also
sounds like you, that is a reason to expect more from it, not less.
This is general information, not a diagnosis, and it cannot examine you.
If it matches you, use it to ask better questions of a clinician rather than to replace one.