Authorities are searching for an at-risk woman who was last seen in Redwood City earlier Tuesday afternoon.

The San Mateo County Sheriff's Office is asking for the public's help in locating 67-year-old Alzheimer's patient Margaret Woodman, who walked away from her doctor's office in the 100 block of Arch Street, near Hopkins Avenue, around 1 p.m.

Woodman, a Redwood City resident, was last seen wearing a white jacket with colored bows and black pants.

She is described as 5 feet 6 inches tall and weighing 110 pounds. She has brown eyes and brown hair.

San Mateo County sheriff's Deputy Rebecca Rosenblatt said Woodman has walked away on previous occasions. This is the third time since the end of January she has been reported missing.

Anyone with information about Margaret's whereabouts is asked to call 911.