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The most common cause of these symptoms would be acid reflux, also called gastroesophageal reflux disease, or GERD. It is common for GERD to cause chest pain, and it is also common for GERD to get worse at night when lying down. While sitting or standing, gravity helps to keep the stomach contents in the stomach, but when lying down, gravity no longer helps, and the stomach contents can more readily reflux into the esophagus.
Antacids are fine to use for GERD, although they are frequently not strong enough. Using a stronger medicine to suppress stomach acid is usually more effective, such as ranitidine or omeprazole.
Many people also find that it can help to place 4-6 inch blocks under the feet at the head of the table. It also is reasonable to avoid oral intake for several hours before going to bed, so that the stomach is more empty when you lie down.
If these interventions relieve the symptoms, then it is not necessary to pursue any evaluation, but if the symptoms persist, it would be appropriate to see your doctor to pursue further evaluation to make a definitive diagnosis.
If I can provide any additional information, please let me know.