DISTRAUGHT family members of a missing Ballarat woman have appealed for information about her disappearance.Speaking on behalf of Karen Gilligan's family, Detective Senior Constable Steve Campbell, from Ballarat Criminal Investigation Unit, said the disappearance of the mother-of-four had rocked her close-knit family.Ms Gilligan, 44, who suffers from a medical condition, has been missing from her Ballarat home since March 25. Her disappearance was reported to police soon after.Det Sen Const Campbell said Ms Gilligan's disappearance was out of character."Her family is distraught. They are close-knit family who kept in constant contact with each other. The disappearance is very unlike her,'' Det Sen Const Campbell said.In the afternoon of March 26 — the day after her disappearance was reported by her adult children — there was a positive sighting of Ms Gilligan at Avoca. Later the day her car, a red 1993 Holden Barina sedan, was found on the roadside in Show St, near Mount Rd, at Wycheproof.A number of inquiries were made by police soon after Ms Gilligan went missing and a police and State Emergency Services search of the area where her car was found was conducted earlier this week.Det Sen Const Campbell said she had not been seen or heard of since. He said her bank cards had not been used since her disappearance.Ms Gilligan suffers from a medical condition that requires prescription medication. Det Sen Const Campbell said the medication would have run out five weeks ago and she had not sought a further prescription.Ms Gilligan is described as 165cm tall, of medium build with a fair complexion, fair hair and green eyes. A description of the clothes she was wearing at the time of her disappearance was unavailable.Anyone with information about Ms Gilligan's disappearance can contact Det Sen Const Campbell at Ballarat CIU on 5336 6080 or CrimeStoppers on 1800 333 000.