valetudinarian

adj. chronically worrying about one's health; constantly in poor health

n. one who worries chronically about his health; invalid

Noun
1. weak or sickly person especially one morbidly concerned with his or her health
(hypernym) sick person, diseased person, sufferer
Adjective
1. of or relating to or characteristic of a person who is a valetudinarian

(n.)
A person of a weak or sickly constitution; one who is seeking to recover health.
  

(a.)
Of infirm health; seeking to recover health; sickly; weakly; infirm.
  

A person who is obsessed with some ailment

Synonyms and related words:
alcoholic, alternating personality, antisocial personality, apoplectic, arthritic, cachectic, case, consumptive, debilitated, disordered personality, disturbed personality, double personality, drained, drug user, dual personality, dyspeptic, emotionally unstable personality, enervated, epileptic, escapist, exhausted, failing, feeble, frail, healthless, hostile personality, hypochondriac, hypochondriast, idiot, imaginary invalid, immature personality, in poor health, inadequate personality, incurable, inferior personality, infirm, inpatient, invalid, languishing, malade imaginaire, maladjusted personality, mentally defective personality, moral insanity, moribund, multiple personality, neuropath, neurotic, neurotic personality, outpatient, pale, paranoid personality, patient, peaked, peaky, perverse personality, psychoneurotic, psychopath, psychopathic personality, psychotic, psychotic personality, reduced, reduced in health, rheumatic, run-down, schizoid, schizoid personality, seclusive personality, sexual psychopath, shut-in, shut-in personality, sick person, sickly, sociopath, spastic, split personality, sufferer, terminal case, the sick, unhealthy, unsound, valetudinary, weak personality, weakened, weakly, with low resistance