It was poison.

"When big brother was sixteen years old, he suddenly fell ill and couldn't get up. The family had invited many spirit alchemists to take a look, but they couldn't find the cause of the illness at first. Later on, they said it was an innate pulse blockage disease. If this disease appeared in an ordinary person, it wouldn't matter, but if it was a cultivator with good talent, once they reached the monarch level and above, their meridians and Qi sea would gradually shrink because of the impact of their own meridians, and eventually become a waste." Ling Yitong replied. There was a hint of worry and worry in his tone, as well as some indignation.