The lungs are the largest organs in the Yol-Taeyangin, so the upper jiao, the lung group (lungs, esophagus, tongue, ears, brain, skin) is the most developed. Pancreas follows as the relatively large organ, so the upper middle jiao, the pancreas group (pancreas, stomach, breast, eyes, spine, muscles) is well developed. Kidneys are relatively small, so the lower jiao, the kidney group (kidneys, large intestine, sex organs, mouth, bladder, bones) is not well developed. The smallest organ is the liver, so the lower middle jiao, the liver group (liver, small intestine, navel, nose, waist, hypodermic tissues) is least developed.

The Yol and Han-Taeyangins both have the lungs as largest organs and liver as the smallest, but they are still different in their external body shape, because the relative sizes of the two middle organs, pancreas and kidney, are different.

It is important that, although both have the organ structure 'lungs > liver', the Yol-Taeyangin is characterized by the largest lungs, while the Han-Taeyangin is characterized by the smallest liver. In other words, the Yol-Taeyangin is a constitution caused by lungs that are too large, while the Han-Taeyangin is a constitution caused by a liver that is too small.

If these constitutions somehow become ill, the large lungs of the Yol-Taeyangin become stronger and the main cure is to adjust those strengthened lungs. In the case of the Han-Taeyangin, the small liver will become even weaker, and the main cure is to adjust that weakened liver.

This can be easily expressed as below.

Above: Constitution with lungs that are too large: the Yol-Taeyangin
Below: Constitution with liver that is too small: the Han-Taeyangin

As seen above, although the Yol-Taeyangin has the lungs as the largest organs same as the Han-Taeyangin, the two lungs cannot be regarded as equally large. It is evident, that the Yol-Taeyangin's lungs are larger.

Although the Han-Taeyangin has the liver as the smallest organ, same as the Yol-Taeyangin, the two livers cannot be regarded as equally small. It is evident, that the Han-Taeyangin's liver is smaller.

By organ structure, the Yol-Taeyangin (lungs > pancreas > kidneys > liver) is the opposite of the Han-Taeumin (liver > kidneys > pancreas > lungs). They have various characteristics that are opposites.

It is important, that even though the difference is small, the Yol-Taeyangin hardly puts on extra weight, same as the Han-Taeyangin. That is strange, because the Yol-Taeyangin should be prone to becoming fat as the opposite of the Han-Taeumin, who almost can't become overweight. In the organ structure of the Yol-Taeyangin the pancreas is the second largest organ, so we could think that his good digestion would make him fat. But to become corpulent one must have from birth either the pancreas as the largest organ, like the Yol-Soyangin, or at the same time have large liver and pancreas like the Yol-Taeumin. Even though the Yol-Taeyangin's pancreas is large, it isn't the largest organ like that of the Yol-Soyangin. Besides, the Yol-Taeyangin's liver is the smallest organ. Therefore the Yol-Taeyangin doesn't become much fat.

In summary, Taeyangin doesn't become fat, neither the first nor the Han-Taeyangin; among corpulent people you won't find Taeyangins. Some scientists attribute the Taeyangin's not being corpulent also to his vigorous mental activity due to his well developed brain.

Because of his large pancreas he can eat and digest well anything, but greasy foods put an undue burden on his weak liver. So for his health meat is not good, and vegetables are good.

He is progressive and decisive and begins things without fear. He depends more on inspiration of the moment or intuition than on detailed anticipatory preparation; therefore he often fails. Nevertheless, he doesn't much regret it.

He has a strong will and hardly listens to others. Through acting on such strong will, he can become either a hero or be ignored by society.

Taeyangin tends to deny the real world and endlessly seeks a better future. He is radical and wants reform. He has an idealistic or revolutionist temperament.

He speaks well either in private or before the public. Career is important to him and he is power hungry. He is quite interested in politics. Indeed many are outstanding in that field.

He makes friends easily and is not offended by them. He acts freely without thinking about it.
His mental activity is very vigorous and he has many immediate thoughts and ideas. But sometimes due to lack of fulfillment his ideas remain only ideas or fall into other's possession.

The Yol-Taeyangin has small kidneys so a woman's uterus is not well developed. She can be sterile or not fertile. Because of his small liver and kidneys the Yol-Taeyangin has a weak lower body, and therefore likes to sit leaning against something or lie down and can't remain sitting, standing or walking for long. Generally the Yol-Taeyangin has a large head because of the well developed brain and has brilliant eyes due to the large pancreas.

Taeyangins from birth have healthy bodies and seldom become ill. The Yol-Taeyangin has a stronger body than the Han-Taeyangin. However, if they do become ill, medicine, either chemical or herbal, will not work well or may even be limited to side effects.

They like fresh and simple foods. If they eat salty or hot spicy foods for a long time, the stomach will be injured and they'll easily suffer indigestion, spasms of the esophagus, or esophagostenosis.
Lee Jema says that if Taeyangin perfects his personality, he becomes a contributor to the human race; otherwise he becomes the most ignoble fiend.