There are many conditions that can make breathing difficult. Conditions that affect the lungs and airways such as asthma and pneumonia cause breathing problems. If the heart is diseased and is unable to pump sufficient blood to supply oxygen to the body this can also make it hard to breathe as can stress and anxiety. If you often have trouble breathing, it is important to find out the cause. Often babies and children will have difficulty breathing or may stop breathing altogether. This section looks at how chest conditions are diagnosed and the common causes of breathing difficulties including acute asthma, allergic reactions (anaphylaxis) and bronchiolitis, as well as what can be done in an emergency.