Earlier this year the dancer, who has been a Strictly pro since 2017 and danced with celebrities including musician Tom Fletcher, comedian Brian Conley and presenter Karim Zeroual, revealed the news she had been diagnosed with stage 3 breast cancer.
Doctors have also found tumours in other parts of the 33-year-old Welsh dancer’s body and previously underwent a single mastectomy. She is now undergoing chemotherapy treatment.
The BBC star took to Instagram on Thursday to share a hospital selfie of her connected to an IV as she held up a high five, reflecting the chemo round she was about to start.
The dancing pro captioned the shot: “Chemo 5 [tick emoji]”.
On Instagram, the star was seen dancing with some of her loved ones with a baseball cap on her head, before she removed it and put it over the camera.
After a moment, she revealed her newly-shaved head while her family dance in the background.
Dowden revealed in the post that fellow Strictly pro Dianne Buswell had inspired the video.
In the caption, Dowden wrote: “When @diannebuswell sends you reel ideas!”
“Fair play dad @richard_dowden you steal the show here with your performance and energy #showman! This brought so much fun to the day! As dancing always does,” she added.
A number of her famous friends and Strictly dancers praised the clip - and the dancing of her father, Richard.
Buswell wrote: “Yessssssss look at you all. @richard_dowden it’s a 10 from me.”
Last week, the star revealed in an Instagram post that she had decided to remove her hair to take back some “control.”
Dowden is not taking part in Strictly this year due to her illness.
She did appear in a title sequence alongside other pros in last weekend’s opening show.
She was also referenced in the launch show as presenter Tess Daly called her “our Welsh Dragon.”
Co-host Claudia Winkleman added: “Amy, from your entire Strictly family we are sending all our love and we can’t wait to have you back on the dancefloor.”
Strictly Come Dancing continues on Saturday at 6:20pm on BBC One.