His boyhood and youth were sickly, for at ten he had general dropsy, at twelve smallpox, at fourteen tertian ague, and at twenty-one measles with profuse bleeding from the nose.
After a short residence in Bristol he settled in practice in a marshy part of Somerset, where in 1652 he had a severe fever, then epidemic, followed by a quartan ague, which weakened him so much that he decided to leave the district.
The Duke of Hamilton, the Duchess of Ormonde, the Marchioness of Antrim, Lord Stafford, and General Talmash or Tollemache, afterwards mortally wounded at Brest, were among his patients, and he cured Captain Harrison, son-in-law of Bishop Jeremy Taylor, of lead palsy.
In 1689 he visited London, and, having been nominated in James II's new charter to the College of Physicians, was admitted a fellow on 19 March 1689.
He is probably the first English writer who noted the now well-known occurrence of acute rheumatism as a sequel to scarlet fever (History of the Bath, p. 12); and his account of Major Arnot's case (p. 45), in which muscular feebleness of the arm followed the constant carrying of a heavy falcon on one fist, is the first suggestion of the morbid conditions now described as ‘trade palsies.’ The lympho-sarcoma of the pericardium, which he discovered post mortem in the case of Sir Robert Craven, is the first described in any English medical book.