Brooke, 25, is believed to have broken his collarbone and suffered a suspected collapsed lung when riding Old Storm in a novices' handicap chase on Saturday.
Racing was delayed for almost two hours as medical staff treated Brooke after his mount's fall.
"Hope not to be out for too long," he posted on social media on Monday.
"Thank you so much for everyone's support and well wishes!"
The Injured Jockeys' Fund released a statement on Sunday saying the doctors at Royal Victoria Infirmary in Newcastle, where Brooke was transferred by air ambulance, were "pleased with his progress".
Jockey Henry Brooke says he is "on the mend", a day after he was brought out of an induced coma following a fall at Hexham racecourse.