Lesser known reasons for muscle pain are fever, the flu, some diseases (e.g. many rheumatic conditions, Myofascial Pain Syndrome, shingles ), dehydration, a virus, a flu shot, surgery or taking medicine (e.g. a side effect of Simvastatin for cholesterol reduction).

Many people think that their muscles are inflamed when they feel too much pain, but inflammation is characterized by swelling and redness in addition to pain¹.
Such inflammation can result when an injury to a muscle, tendon or another part of the body has occurred.

In reality, muscular pain is created by small contracted fibres in a muscle or its surrounding fascia: so called myofascial trigger points (“myo” means “muscle”).

The more often muscles are affected by the above-mentioned causes the more fibres remain in a contracted state which usually goes unnoticed for a long time. Then the day comes when your body can not compensate anymore. You might suddenly feel widespread pain from all the trigger points that have accumulated over time.

These sore points have been latent / sleeping in your body and were activated by a seemingly small exercise or movement. Sometimes they become painful by a disease or fever, or a sudden impact (e.g. car accident) and you can feel severe pain throughout your body.