Unexpected breathing difficulty can signal a serious medical condition.
Sudden shortness of breath may occur with heart problems, lung conditions, or other medical emergencies.
Breathing difficulty may happen during physical activity or while resting. In some cases, it may appear alongside other symptoms such as:
• Chest discomfort
• Rapid or irregular heartbeat
• Sweating or dizziness
• Extreme fatigue
If breathing becomes difficult while resting, lying down, or speaking, it may signal a serious health issue.
Do not ignore sudden breathing problems, especially if they appear without a clear cause.
Emergency Action
If shortness of breath is severe, sudden, or worsening, call 911 immediately.
Source
CDC