Ashtangasamgraha 23.24

23.24

nivṛtto 'pi punarvyādhiralpenāyāti hetunā |

dehe mārgīkṛte doṣaiḥ śeṣaḥ sūkṣma ivānalaḥ ||

prasvidyaṃśca dhanuṣkampī daśarātraṃ na jīvati ||

tatpūyaraktamākhyātaṃ śirodāharujākaram ||

Even when a disease has resolved, it returns through a slight cause,

When the channels of the body have been opened by the doṣas, like a remaining subtle fire.

And sweating, shaking like a bow, he does not survive ten nights.

That is declared to be pūyarakta, producing burning and pain in the head.