The "Wrecking Ball" hitmaker has been receiving treatment in a hospital after suffering from severe allergic reaction to antibiotics.
Cyrus, 21, informed her more than 17 million followers that she had been catching up with her reading.
"Reading books so I don't die a famous pop pop dumb dumb," she wrote.
Prior to writing the tweet, she wished her fans happy Easter and admitted that she was "seriously EMO" because she had to spend her time in bed during the festivities.
Cyrus, who was forced to postpone the rest of her tour dates, also shared a photo of her wearing a duck-face oxygen mask.