When You Ache All Over
Muscle pain that affects a small part of your body is usually caused by overuse — sore arms from lifting boxes all day, for example. Or it could be a minor injury, like a bruised shoulder after a fall. But when you ache all over your body, it’s more likely caused by an infection, illness, or medicine you’ve taken.
Blood Flow Problem
If you have pain in your arms, legs, or both, your muscles may not be getting enough blood — a problem called claudication. At first, you may notice it only when you exercise, but in time, you might feel it when you sit or walk. This is usually caused by a condition called arteriosclerosis, which is when there’s blockage in the tubes that carry blood to your muscles.
 Hypothyroidism
This is when your thyroid gland doesn’t make enough of certain key hormones. It can cause muscle and joint aches, as well as swelling and tenderness. It can make you tired and lead to memory problems, thinning hair, dry skin, high cholesterol, slowed heart rate, and other issues. Your doctor can do a simple blood test to find out if you have it, and if so, drugs can help replace the missing hormones.
The Flu or Other Infections
When a flu virus hits, it brings on fever and congestion, and it can make your muscles ache, especially in your back, legs, and arms. It usually gets better on its own in a week or so, but call your doctor if it doesn’t. You also should see them if you have other health problems and you get the flu or you have a cough that doesn’t go away. Other infections can also give you muscle aches, including  COVID-19 and HIV.
Medications
Drugs called statins are used to control high cholesterol, and about 30% of people who take them say they have muscle pain. If this is happening with you, talk to your doctor. They may be able to give you a different medication.
Lupus
This is a kind of autoimmune disease — it causes your immune system, which normally helps protect your body, to attack your tissues and organs. When lupus affects your joints or muscles, it can make them stiff, and it can hurt to move. There’s no cure, but medication and certain exercises can help control your symptoms. Talk to your doctor about what would work best for you.
Rheumatoid Arthritis
This is also an autoimmune disease — it mainly affects your joints and can lead to bone loss. It can cause pain and inflammation all over your body, and your joints may swell into odd shapes. Medication and physical therapy can help with your symptoms, but there’s no cure. In some cases, you may need surgery to repair the affected joints.
Dermatomyositis
This autoimmune disease makes your muscles and joints ache and causes painful, itchy, red or purple rashes on your eyelids. It also makes spots on your knuckles, elbows, knees, and toes, can dry your skin, thin your hair, and cause swollen, irritated skin around your fingernails. It can be triggered by infection, drugs, or cancer. There’s no cure, but your doctor can help you manage your symptoms with drugs and physical therapy.
Polymyositis
This happens when something — possibly a virus or a problem with your immune system — inflames muscles all over your body, especially in your belly, shoulders, upper arms, hips, and heart.
Over time, your muscles can start to break down, and it might be hard to swallow or catch your breath. Your doctor may suggest drugs to ease inflammation or calm your immune system and physical therapy to help you regain muscle strength.
Chronic Fatigue Syndrome
The main symptom of this condition is extreme tiredness (fatigue) that can’t be explained by anything else. It may get worse with exercise or mental strain, but rest doesn’t make it better.
You also may have muscle pain, memory problems, sore throat, joint pain, and headaches, and you may not be able to sleep well. There’s no cure, but medication and physical therapy can help manage your symptoms.
Source: webmd.com
