Helen so desperately needs help with her elderly mother Elizabeth that she’s turned to younger brother Teddy. He shows up a day late just before Helen must leave to catch a plane for an important conference.

Teddy, who’s just finished a tour with his band Dog Hair Sofa, is so unnerved by his mother’s dementia that he calls Lucy, Elizabeth’s former caregiver, whom Helen fired for stealing Elizabeth’s jewelry. Lucy is reluctant to get involved with the family again but cares for Elizabeth and is drawn to Teddy.

That is how Kate Hawley’s poignantly funny “Complications from a Fall,” playing at Portland Stage Company through Nov. 12, opens. The characters are engaging yet realistic and the performances are utterly believable.The dialogue informs but doesn’t preach and the revolving set quickly allows the action to switch from Elizabeth’s living room to her bedroom and back. The play will ring true for anyone who has dealt with an aging relatives with dementia.

The two-act play, which was based on Hawley’s experience in dealing with her own aging mother, premiered in April 2015 at the Jewel Theatre Company in Santa Cruz, California. The Portland production is the show’s Maine premiere.

Director Paul Mullins lets the characters pace the show. The first scene feels frantic because Helen (Eva Kaminksy) is in a frenzy about Teddy (Erik Saxvik) arriving a day late. Later scenes evolve at a more leisurely pace as Elizabeth (Maureen Butler) opens up about her childhood and Teddy courts Lucy (Katie O. Solomon).

Kaminsky’s Helen is so tightly wound that when she gets drunk and cuts loose at a karaoke bar, the result is hysterical and familiar to anyone who has ever been to one of “those” drinking establishments. Her need to find validation in her career as a Henrik Ibsen scholar after caring for her mother is funny because Helen takes herself so seriously but it also is painfully palpable. Helen is not a likable character but Kaminsky’s performance has so much depth, she makes the audience feel sympathetic about her plight.

As Teddy, Saxvik is charmingly clueless about Elizabeth’s illness but his portrayal is so heartfelt that it’s impossible not to love the irresponsible musician. It is through Saxvik’s open and engaging performance that the audience learns of Elizabeth’s difficult childhood and accessing her emotionally.

Solomon’s Lucy is practical but vulnerable. The actress perfectly portrays how torn the character is between caring for Elizabeth and being outraged at being fired and accused of stealing. Solomon and Saxvik achingly portray the passion bubbling just beneath the surface.

As Elizabeth, Butler shifts forward and backward in time and place effortlessly. The actress makes the character’s past so fascinating, the audience eagerly travels there with her wanting to stay, even though Helen and Teddy resist the journey. Butler gives a finely nuanced performance that reveals the young woman Elizabeth once was.

The pace of the show is helped immensely by Anita Stewart’s revolving set that include a wall that is lifted into the fly space to allow Helen’s activities at her conference to be easily seen. Stephen Jones’ lighting design and Andrea Hood’s costumes work seamlessly with Stewart’s set.

“Complications from a Fall” is interesting and heartfelt theater. Dealing with an aging parent suffering from memory loss is a reality for many in Maine due to the state’s demographics. Portland Stage’s production not only shines a light on dementia, the playwright’s humorous approach offers a salve for caretakers who feel they are coping alone with little support.