Chest tightness is a feeling of pressure or squeezing in the chest. It can range from mild to severe and can be accompanied by shortness of breath, difficulty breathing, and/or pain. It can develop suddenly or gradually, and may be triggered by physical or emotional stress, or by an underlying medical condition. Symptoms may include a feeling of heaviness, burning, or aching in the chest, and may worsen with deep breaths, coughing, or physical exertion.