ME commonly starts with abdominal pain and diarrhoea, together with a persistent headache and / or vertigo, with a stiff neck and back, together with generalised myalgia, described as intense and burning. Muscles are tender to palpation and muscle spasm is not uncommon. There may be severe, intractable pain in particular groups of muscles, most notably in the neck and in the shoulder and pelvic girdles: the more severely affected are unable to stand unsupported for more than a few minutes. There is sometimes segmental pain in the chest wall.