from one another when being diagnosed?

All of these diseases are very complicated to diagnose because they have simliar symptoms. there are no easy tests that give a yes or no answer. Lab tests, medical history and symptoms AND ruling out other disorders AND having an experienced clinician can lead to a diagnosis.

Basically, there is no simple answer.

Fibromyalgia is a muscle disorder that is not as serious as the last two, and lupus is a connective tissue disorder. Lyme disease is an infection and in that sense is unrelated to the first two. however, if not treated, in its third stage Lyme disease can go on to affect joints.

Fibromyalgia is stiffness and pain felt in fibrous tissues, usually deep within the muscles. it seems to be accompanied by emotional tension reflected in the knotting up of muscles. there is nothing basically wrong with the muscles themselves. Yet localized pain is likely, and there may be even slight swelling within the affected muscles. it often causes a backache.

In lupus, connective tissue in any part of the body may become inflamed, damaging the skin, joints, and internal organs. the immune system forms antibodies against cell nuclei, DNA and RNA, cell proteins, phospholipids, red and white blood cells, and other structures. these antibodies become jointed to their targets as immune complexes that provoke the inflammation.
Because the disorder affects so many body systems, general symptoms are common, including fatigue, a sense of ill health, loss of appetite, loss of weight, and fever.
The skin is affected in 80% of cases, usually with a butterfly-shaped rash over the cheeks and the bridge ofthe nose. a more general rash often affects those areas of the skin exposed to sunlight. Partial or complete hair loss may occur. Skin ulcers and skin nodules may form.
Around 95% of people with lupus have some problems with their joints and muscles, with pain more common than deformity. about 85% have anemia or another blood disorder, including either ineffective blood clotting or unwanted clotting in the veins or arteries causing an embolism, stroke, or other problems.
Virtually every body system may be affected – from the eyes to the intestines. Lupus affects mostly women. Because of the blood-clotting abnormalities, miscarriages are common in pregnant women with lupus. the disease often flares up in the early months of pregnancy. nevertheless, many women with the disease have successful pregnancies and give birth to healthy infants.

Lyme disease is a bacterial infection. it is caused by the spirochete bacteria Borrelia burgdorferi, which is transmitted to humans from a bite by an infected tick. usually a red spot develops on the skin that gradually increases in size. the center of the spot returns to its normal color after a day or two, so the skin has the appearance of a bull's-eye. This spot on the skin is very noticeable but may not be painful. in some cases the skin clears up and there are no other symptoms. however, in other cases within a day or two more red spots appear and a headache, fever, swollen lymph glands, and pain in the joints and muscles appear, as well as a feeling of illness and weakness. If Lyme disease is not recognized or treated, the second stage of the illness affects the heart and nervous system. Meningitis and partial paralysis of the muscles served by the facial and other nerves often occur. the meningitis causes severe headache, muscular weakness, and numbness or tingling. Irregular heartbeat and inflammation of the heart and pericardium are common. those who remain untreated move to the third stage of Lyme disease, in which chronic arthritis often develops, usually affecting the larger joints such as the knees.

Unfortunately they all share many and very similar symptoms,i was diagnosed with fibromyalgia,lyme disease,it ended up actually that my body was not getting proper oxygen from lung disease from chemical damage,but because symptoms were so alike ,I was mis -diagnosed.
lupus,is where the body's immune system,turns on itself ,and attacks the body,harming instead of helping. some foreign objects like breast implants,cause immune system to recognise it as a foreign substance,it tries to get rid of it,can;t,so it goes haywire,and attacks itself!
fibromyalgia is a secondary diagnosis or skin,flesh pain,when in actuality its real cause is rarely diagnosed,my fibromyalgia is due to lack of oxygen and damage to blood vessels.
highly diagnosed in people that are stressed,depressed,smoke,and have poor life-style behaviours!