The phrase "What is the matter with him? He has... he should go to the hospital" typically implies that the person is showing concerning symptoms or illness that warrant medical attention. Common reasons to urgently go to the hospital include symptoms like chest pain, difficulty breathing, uncontrolled bleeding, loss of consciousness, seizures, or signs of stroke. Other signs like a very high fever, severe headache, sudden weakness, or mental confusion can also indicate the need for emergency care. In a simpler educational context, this phrase can be completed with something like "He has a fever. He should go to the hospital" or "He has a headache. He should go to the hospital" depending on the specific symptom needing treatment. The use of "should" suggests it is advisable or necessary based on the symptoms observed.

If concerned about someone showing worrisome symptoms, it is best to err on the side of caution and seek hospital evaluation promptly.

In summary, the phrase means the person is unwell with symptoms significant enough that medical evaluation at a hospital is recommended. The exact symptom can vary, but it generally denotes urgency or seriousness.