What are the problem of my stomach lower chest

Treatment :
management of gastric upset depends on the cause which mainly is due to gastritis ,gastritis means inflammation of the stomach which results in abdominal and lower chest pain accompanied by other symptoms such as heartburn ,bloating, nausea and GI disturbance .it can be managed by avoiding spicy or salty or chilly food, avoid eating heavy and large meals, ,don't take NSAIDs drugs because they are harmful to the stomach ,not to sleep or lie down after eating ,stop smoking and reduce the amount of daily coffee intake, and taking drug to inhibit the acid secretion from the stomach such as Omeprazole 20 mg twice a day for a month 
causes:

• H.Pylori infection
• Stomach ulcer
• Duodenal ulcer
• esophagitis
• GERD
• Zollinger-Ellison syndrome

Diagnosis:
based on symptoms and medical history then physical examination and some tests such as Ph. manometry to measure the acidity of the stomach, Stool test for H.pylori,EGD scope to see the stomach and esophageal lining
advice:
follow the instructions above and consult the doctor to run some tests in case your symptoms persist.