Vomiting. What kind of tests do we need?

Based on the symptoms you have described, it is possible that your dad may have experienced a gastrointestinal bleed, which can cause blood to appear in the vomit. This can be a serious medical condition and requires immediate medical attention. As your dad is diabetic, it is also possible that his symptoms could be related to his blood sugar levels. Low blood sugar levels can cause sweating, fatigue, and vomiting, while high blood sugar levels can cause nausea and vomiting. I would recommend that you take your dad to the emergency room or schedule an appointment with me or another medical professional as soon as possible to determine the cause of his symptoms and receive appropriate treatment. Tests such as blood tests, imaging tests, and endoscopy may be necessary to diagnose the underlying cause of the bleeding. In the meantime, make sure your dad is staying hydrated by drinking plenty of fluids and avoiding solid foods until he is feeling better. If his blood sugar levels are low, he may need to consume a small amount of sugar or glucose to help raise his levels. Please let me know if you have any further questions or concerns.