Astanga Hrudaya
शरीरमनुगृह्णन्ति पीडयन्त्यन्यथा पुनः। तत्र श्यावारुणाः सूक्ष्माः पूर्णरिक्ताः क्षणात्सिराः॥३६॥
remaining so (within their normal state) sustain the body, while, on the other hand (in their abnormal state) they cause troubles to the body. Signs and symptoms of the veins carrying doshas: Veins which are bluish-red in colour, small (sometime) full and sometime empty momentarily and having throbbing (pulsations) are carrying blood mixed with Vata;
english translation
zarIramanugRhNanti pIDayantyanyathA punaH। tatra zyAvAruNAH sUkSmAH pUrNariktAH kSaNAtsirAH॥36॥
hk transliteration by Sanscript