Body Aches — Full Text

Body aches, or muscle pains, are called “myalgias” in medical-speak (“myo-” = muscle; “-algia” = pain).  If a single muscle group hurts, it may be a strain, trauma, infection. or tumor, which are pretty easy to sort out.  But aches and pains all over is different; this topic is about the latter:  generalized myalgias.

First step is to be sure we’re talking about muscles, not joints.  Muscles are our meat; joints are spaces where bone meets bone.  People who hurt all over are surely uncomfortable, but are nonetheless able to tell the difference between muscles and joints.  Some patients say they have pain all their “bones.”  But bones can only hurt in specific places; if all the bones hurt, it’s really the muscles.

We also want to be sure that we’re dealing with muscle pain, and not weakness.  Weakness means loss of strength, like not being able to lift your arms over your head, or rise from a chair without using your arms to boost yourself.  Sure, pain can interfere with strength, but a good clinician can tell the difference between true muscle weakness in and of itself, and that which is due to pain.  We don’t have a topic on Weakness yet, but basically new onset true weakness needs to be evaluated in an ER, while patients with chronic weakness need to see neurologists.

Back to body aches & pains (myalgias)  —  as usual, we generate a list of the main possible causes, separating them into those that have begun recently (within the last week or two), and those that are more long-standing.  Our possibilities are:

This topic deals with generalized muscles aches all over, not just one arm, or lower leg, etc.

Causes of Muscle Pains (Myalgias)

RECENT ONSET OF BODY ACHES

When a patient’s muscle ache all over for a few days, they probably have a viral illness.  If they have a fever, that’s for sure what they have.  Almost — see our topic Fever for how to distinguish common viral illnesses (like Covid-19, or the Flu) from rare but life-threatening conditions. Be aware that every office, clinic, etc. has its own way to deal with Covid before they let you inside.

The main obscure disease to add, if a patient had traveled to the tropics, would be Dengue.  It’s often called “breakbone fever” because it feels like all your bones have been broken (though it’s really severe muscle pain, a technicality making no difference in the world to anyone suffering from it).

Even though the following is covered under our topic Fever, it’s worth repeating.  Persons with weak immune systems may have life-threatening infections but only minor symptoms, and even no fever.  This is because it’s the immune system, in its battle against germs, that makes us feel bad (but saves our lives).  So if any of the following patients might experience the sudden onset of general muscle aches, or chills, we might well send them to an ER:

Then there’s Rhabdomyolysis (“Rhabdo”), actual breakdown of muscles which can clog the kidneys, causing permanent damage requiring kidney dialysis, or even death.  We’d worry about this if muscles not only hurt, but were tender to touching them.  The urine might look reddish-brown (from muscle pigment); a simple dipstick test might show lots of blood, but no red blood cells under a microscope.  We’d especially worry about Rhabdo among patients taking Statin medications for cholesterol.

Rahbdo is diagnosed by finding extremely high levels of muscle enzymes on blood tests, especially the creatine (phospho)kinase (CK, or CPK), also the lactate dehydrogenase (LD, or LDH) and the common liver enzyme AST.  Small elevations don’t count.  Since treatment for Rhabdo is emergent, hopefully the results are found same-day through an ER.

Statin medications can cause myalgias without damage severe enough to cause Rhabdo.  Diagnosis is made by stopping the medication and seeing if symptoms disappear within a week or two.  No matter how high the cholesterol was, this is never a problem.  But discontinuing a medication can cause pain relief through placebo, or because the pain might have resolved anyway.  So as long as the CPK was normal, we then ask the patient to resume the statin in a month or two.  If myalgias return, we can be sure it was the medication, & change it somehow.

Muscle cramps, especially in the arms & legs, may be due to extremely low blood levels of calcium or magnesium (this is extremely rare).  The cramps would be ongoing, not just now & then.

See also Body Aches (top section) for the clinician’s condensed thought-process when face-to-face with a patient.

ONGOING MUSCLE ACHES & PAINS  (Chronic Myalgias)

Once muscle aches and pains have been going on for a few weeks at least, we no longer worry about life-threatening illness.  But since Rhabdomyolysis is never something we’d want to miss, & in rare cases can fluctuate in severity, we’d still obtain a blood test for a CK (CPK).  It has to be very elevated to make us concerned, not just a little bit high.  We’ll discuss bone cancer later.

Fibromyalgia is a common cause of generalized muscle aches.  It’s our most likely cause in people under 50.  There’s no test for it, and we can only diagnose it by ruling out all other possible causes in the table above.  So that’s how we proceed.

An inflammatory condition Polymyalgia Rheumatica (PMR for short) is a likely possibility in persons over 50.  It causes stiffness in shoulders, neck, and hips, mainly in the morning when the body had been resting.  We only consider it if an older person has morning stiffness in those areas for at least 30 minutes every day.  There’s no test for PMR; we make the diagnosis by finding suggestions of inflammation by blood tests for a Sedimentation Rate (ESR) & C-Reactive Protein (CRP), and maybe a mild anemia.  If those tests are negative, but we’re still suspicious, we might order a shoulder and hip ultrasound, looking for inflammation of tendons, bursa, or joint.  If we think someone has PMR, we’d ask about headaches or jaw pain of a related condition Temporal Arteritis, which can cause blindness.  If we start treating supposed PMR with steroids, and the person doesn’t feel lots better in 3-4 days, the diagnosis is likely wrong.

For patients with generalized muscle aches, we’d usually get some simple blood tests like a complete blood count, a general comprehensive metabolic panel (CMP), TSH (thyroid test), and also a CK (CPK).  These will help clue us in to a variety of possibilities in our list.  We might also obtain blood tests for chronic Hepatitis B and C, especially if there are liver abnormalities in the chemistry panel.  Rheumatologic diseases usually affect the joints, but can also involve nearby structures like bursa and tendons, so we might order an antinuclear antibody (ANA) as a general screen (useful only if fairly elevated, not just a little bit).

Certainly we find out what medications a patient is taking.  If they’re taking a statin for cholesterol, we’d order a CK (CPK) as above, then have them stop the drug to see if their pains go away.  If so, we don’t congratulate ourselves (since placebo effect is common), but tell them to wait a month and resume the medication.  If symptoms recur, that’s usually enough proof, though we could try the stop & restart again if we’re doubtful.  We’d never have them try the statin again if the CK (CPK) is fairly high.

If all of the above tests are negative, Fibromyalgia will be a likely diagnosis (see below), certainly in persons under 50-years-old.  But first we want to rule out Depression (see link for diagnostic criteria).  Many fibromyalgia patients suffer from depression, but if treating the latter makes aches & pains go away, the mental health diagnosis will be enough by itself.

And what about Bone Cancer?  For it to cause generalized aches and pains, it would have to be widespread.  Bone cancer usually involves a single bone, but Multiple Myeloma (a type of blood cancer) can cause destruction of many bones at the same time.  So can widespread metastatic spread to bone from various primary cancers (especially breast, lung, or prostate).  We think of bone cancer when specific bones (not muscles) are tender to tapping or pounding on them. A blood test for the bone enzyme Alkaline Phosphatase can be quite high.

X-rays can often identify bone cancer.  If negative, CT scans or bone scans may be required.  But we’d only order these if an alkaline phosphatase blood test is elevated (a sign of bone destruction).  We might also pursue our suspicion in elderly patients who are at more risk of cancer, and much less likely to have Fibromyalgia.

We consider Fibromyalgia when a patient has steady pain all over for at least 3 months, normal tests, and no worrisome symptoms like fevers, sweats, or weight loss (if those are present we’d use them as starting points to address diagnosis, instead of the muscle aches).  Traditionally a clinician would press firmly on 18 specific areas of “soft tissue” (muscle, tendon, ligament, and bursa, but not bone); if at least 11 were tender, and other areas not tender, the diagnosis could be made.  However, we can also make the diagnosis if a patient has all of the following:

• pain in many different parts of the body
• significant problems with fatigue, not feeling awake and refreshed, & problems concentrating
• various unrelated symptoms (headache, stomach discomfort, depression, & many more)

See link for a formal Fibromyalgia Scoring System (mainly used in research).

See also Body Aches (bottom section) for the clinician’s condensed thought-process when face-to-face with a patient.