Because with the Yol-Soyangin the pancreas is largest, naturally the upper middle jiao is most developed. That is, the pancreas and all of the organs in that group: stomach, breasts, eyes, spine and muscles. Secondly, the lungs are the medium large organs, so the upper jiao is relatively well developed. This group includes the lungs, esophagus, tongue, ears, brain and skin.
 

The liver is the medium small organ, so the lower middle jiao is not very well developed, including the liver, small intestine, navel, nose, waist, and hypodermal tissues. The smallest of the four organs is the kidney, so the lower jiao is least developed, This includes the kidneys, large intestine, sex organs, mouth, bladder and bones.

In a word, the structure pancreas > lungs > liver > kidneys of the Yol-Soyangin naturally characterizes this constitution's body form. The Yol-Soyangin's body shape is such that the upper middle jiao, in which is the largest organ, the pancreas, is most developed, including the chest. Thus a man with this structure will have a broad chest and a woman will have large breasts.

The relatively large lungs also have influence on the body shape of the Yol-Soyangin. The upper jiao, including the lungs and shoulders, are relatively well developed. So naturally the Yol-Soyangin has the best developed upper body with wide chest and shoulders.

The small liver and smallest kidneys respectively represent the lower middle and the lower jiaos. The organs in those groups, for example waist and hips, are not well developed and so look comparatively smaller and weaker than the chest and shoulders.

When observing the shape of someone's body, one must, of course, compare the various parts of the same person's body. There are no absolute criteria for their sizes. In other words, one should compare his chest and shoulders with his waist and hips, and judge their relative sizes.
The constitutional characteristic of the Yol-Soyangin, the teyanginesque soyangin, is that the pancreas is the largest organ. He can digest food well, so he easily gains weight or even becomes obese if he doesn't check his tendency toward eating too much.

Because of the largest pancreas he has good digestion, and in contrast, due to the small kidneys, he has difficulty with bowel movements. This lack of balance causes corpulence. Among the eight constitutions, only those with the larger or largest pancreas can become obese.

Sumo is a Japanese wrestling sport whose professionals have a unique body form. Almost all of them are Yol-Soyangins or Yol-Taeumins. They have a very large pancreas and stomach from birth and digest well everything that they eat. However, that doesn't mean that every Yol-Soyangin will unconditionally become corpulent. They have only that tendency, but many have ordinary body shapes.

According to the organ theory of Lee Jema , muscles belong to the pancreas group, so the Yol-Soyangin has better developed muscles than others. He has a strong body and likes sports. His muscles are easily developed, so if he cultivates his body, he can be proud of his most outstanding physical beauty. He easily gains weight, so many of the shot-putters, weight lifters and other athletes are Yol-Soyangins.

Eyes, too, belong to the pancreas group, so soyangins have a bright shine in their eyes and a good sense of visual beauty because of their good eyesight. Depending on the individual, sometimes the eyeballs project forward. Generally the eyes are very bright and impressive, and in some cases, a few people find it difficult to look directly into their eyes.

Lungs in the Yol-Soyangin are second largest, influencing the lung capacity and vocal chords, so successful opera singer like Luciano Pavarotti, for instance, is typical Yol-Soyangin. This is a characteristic of a teyangin with largest lung capacity, but is a result of the fact that the Yol-Soyangin is combined with Taeyangin.

Another result of this mixture with Taeyangin is that the Yol-Soyangin is temperamentally progressive, creative and imaginative, due to the large upper jiao and evolved brain that belongs to it.

On the other hand, the smallest kidneys influence the lower jiao (to which the kidneys belong), and the Yol-Soyangin has chronic lumbar pain due to a weak waist. Besides, the large intestine (part of the lower jiao) is small and weak, so he easily suffers diarrhea or constipation. The Yol-Soyangin usually sits leaning backward or leaning against the back of a chair. Therefore he can at first glance seem arrogant, but in fact the reason for sitting that way is that his upper body is more developed than the lower body, and is heavier.

The upper body is well developed while the lower body is weak. It follows, that many are not fond of long walks, and prefer to ride. Thus, the weak lower body becomes even weaker, so it is useful for their health to practice sports which strengthen the lower body more than the upper. Walking, running, bicycling and mountain climbing are examples of such sports that use the feet a lot. The more a Yol-Soyangin practices that kind of sports that balance out the strength of the lower and upper body, the better will be his health.

If a Yol-Soyangin gets fat, the extra weight goes mainly onto the upper body, because constitutionally he has well developed upper middle and upper jiaos and so from birth a well developed upper body.

Heat from the most developed pancreas is the main force for digesting well all foods. So the Yol-Soyangin easily gains weight even with little food, and has the biggest appetite. Due to his good digestion he doesn't have indigestion in spite of some excessive eating. Therefore he often eats too much. If he often eats a lot of spicy foods, eats irregularly, or eats too much at once, even with the strongest pancreas he will get indigestion. In that case, it is difficult to cure.

The Yol-Soyangin has a small liver, so he must restrain himself from drinking. However, many of those who like to drink a lot are Yol-Soyangins. This may be due to the constitutional inclination to eat and drink. But eating and drinking too much will inevitably bring many chronic illnesses. Many obese people, diabetics and sufferers of hypertension and arteriosclerosis have this constitution. Wine, beer and cognac are appropriate for this constitution, but whiskey and vodka are not.

Relative underdevelopment of the lower body compared to the upper body means that not only the external body shape is not well developed, but also the organs that belong to the lower body. So the Yol-Soyangin has a weak waist, urinary tract and sex organs, and these areas will be ill relatively often. For example, a woman with a very developed upper body will have trouble giving birth or conceiving. She complains of frequent urination because of a weak bladder and has menstrual pain and an early menopause. A man may complain of chronic lumbar pain, easily suffer from urethritis and early ejaculation, and often has weak energy in old age.

The Yol-Soyangin tends to walk quickly, because the lower body is not developed and light. He goes with an easy motion, swinging both shoulders or looking into the distance.

Of the eight constitutions, the Yol-Soyangin is born with the strongest yang, maybe because this constitution is the mixture of the two yang constitutions: Soyangin and Taeyangin. The Yol-Soyangin contains much warmth principally in the upper body from the warmth of the pancreas and the stomach. Therefore he prefers cold food and drinks cold water even in the middle of winter. Food with a warm character is not good for a Yol-Soyangin. If he continues to feed himself those kinds of foods, they will increase the latent warmth too much and put the body even more out of balance.
Korean ginseng, known as a miraculous panacea, has a warm character, so it is harmful to the Yol-Soyangin, although useful to many others. Also honey, royal jelly, chicken and mutton have warm characters. A Yol-Soyangin is better off not eating such foods as much as possible. Pork, on the other hand, has a cold character and is very good for him. Beef is acceptable to a degree, but generally it's better for his health to eat vegetables instead of meat.

In that way, foods that we often eat daily can be divided into foods that are good or bad depending on the constitution. This is a unique aspect of constitutional medicine, based on the thinking of Oriental medicine that food and medicine have the same roots.

The fact, that the Yol-Soyangin has the strongest yang, influences not only the physiology and pathology, but also the temperament and character that he is born with. The Yol-Soyangin has the most yang temperament. The general characterization of the Yol-Soyangin is of an impatient, strong, direct, extraverted and manly character. The manliest of men, or if a women, she is energetic, kind and active.

The Yol-Soyangin is intuitive, quick thinking, adaptive, clever, progressive, and inclined toward fairness. He likes to work outdoors and to serve others. He is very self-confident and is inclined to start doing something without hesitation. This is caused by the influence of the strong yang.
However, when he does something, he doesn't completely prepare or plan for it. He gets tired of things easily and often quits in the middle of the job. He treats things according to his humor or emotion and is too frank and can't hide or control his emotions. This leads to frivolous conduct. Again, this is due to the fact that the Yol-Soyangin has too much yang in his character.

The Yol-Soyangin is very sensitive. He gets excited easily, gets emotional easily, and sheds tears easily. He speaks without thinking and does whatever he wants; this sometimes leads him to deeply hurt other people emotionally.

Lee Jema said that if a soyangin develops his personality, he can become a great force for justice and be respected by many; otherwise he may become the most frivolous of people. From this viewpoint, his medical theory isn't just for curing people's physical ailments, but also aims to help people develop themselves by being conscious of themselves and by defeating their limits.

It is important to know that the above constitutional characterizations vary according to the individual. Not all Yol-Soyangins are corpulent. From life-style, environment, and constitutional factors from birth, people have various bodily forms. Similarly, even though people have the same constitution, they are different to some extent in temperament, physiology and pathology.
For example, Soyangin has a direct and extroverted temperament, but not all are like that to the same degree; there are differences between them. One soyangin may be too direct and extroverted, while another may be less so. This is due to the degree of yangness factors received from birth and the efforts toward self cultivation made after birth.