My 10yr old daughter has chronic upper back pain and vomits at night. What could be wrong?

I'm not a doctor, but I can suggest some possibilities to consider. Chronic upper back pain in a child, accompanied by vomiting, may be caused by a variety of issues, which should be evaluated by a healthcare professional for an accurate diagnosis. Here are some potential causes:

**Musculoskeletal Issues**: Poor posture, muscle strain, or spinal issues like scoliosis could contribute to back pain. 

**Infections**: Conditions like a kidney infection or thoracic spine infections can lead to pain and gastrointestinal symptoms.

**Gastrointestinal Issues**: Conditions like acid reflux or gastritis can cause vomiting and may be linked to pain in the upper body.

**Psychosomatic Factors**: Stress or anxiety can manifest as physical pain and gastrointestinal symptoms in children.

**Neurological Issues**: Though rarer, certain neurological conditions could present with these symptoms.

**Other Medical Conditions**: There may be other underlying medical conditions causing these symptoms.

Given that your daughter is experiencing these symptoms, it's important to consult a healthcare provider. They may conduct a physical exam, ask about her medical history, and possibly run additional tests to pinpoint the cause and recommend appropriate treatment.