| H/A | head to abdomen; headache |
|---|---|
| HID | headache, insomnia, depression [syndrome]; herniated intervertebral disc; human infectious dose; hyp... |
| HUI | headache unit index |
| IHS | idiopathic hypereosinophilic syndrome; inactivated horse serum; Indian Health Service; integrated he... |
| MCH | Maternal and Child Health; mean corpuscular hemoglobin; muscle contraction headache |