Difficult breathing, (from Dyspnoea 3110 difficulty, and to breathe). Dyspnoon. This is a genus of the class neuroses, and order spasmi. Dr. Cullen defines it to be a constant difficulty of breathing, without a sense of straitness in the breast, but rather that of fulness and obstruction; a cough frequently attending through the whole course of the disease. He distinguishes eight species.

1. Dyspnoe'a catarrhalis, when with a cough there are copious discharges of viscid mucus, called also asthma catarrhale, pneumodes,pneumonicum, and pitui-tosum.

2. Dyspnoe'a sicca, when there is a cough without any considerable discharge.

3. Dyspnoe'a aerea, when the disease is much increased by slight changes of the weather.

4. Dyspnoe'a terrea, when earthy or calculous matters are spit up.

5. Dyspnoe'a aquosa, when there is a scarcity of urine, and oedematous feet, without any symptoms of a dropsy in the chest.

6. Dyspnoe'a pinguedinosa, from corpulency.

7. Dyspnoe'a thoracica, when parts surrounding the chest are injured or deformed.

8. Dyspnoe'a extrinseca, from manifest external causes, asthma pulverulentorum, and metallicum.

It is spoken of by many as a species of asthma; but much difficulty attends this view of the complaint, and us much in affording relief. If respiration be only obstructed and quick, without the other symptom, it is called dyspnaea; if attended with different symptoms, they give an appropriate name. To this place belong several of the species of the orthopnoea, to which the reader is referred.

It is, in general, a spasm affecting the vital functions. Sauvages defines it, a disease whose principal symptom is a shortness of breathing, with chronic indisposition, not intermitting, and without signs of hydrothorax or empyema. Its most usual causes are, phlegm lodged in the bronchiae, or the too strong constriction of the bronchiae themselves, which prevents the easy ingress of the air into the lungs. Sauvages enumerates no less than twenty-two species: but the greater number are symptomatic; and few, if any, admit of more effectual remedies than such as mitigate their violence. It is generally advisable to moderate the plethora in the lungs, and avoid all hurry of respiration.

Sometimes nauseating emetics are good expectorants in this case, especially if given in small doses. Gum ammoniacum, and asafoetida, may be employed; and blisters are often beneficial. Issues have been formed in the thigh; and in some cases seem to have been useful, but in too many instances fail. See Asthma.