| Reaction | |
|---|
| Hallucinations (157) | |
| Hallucinations, auditory (48) | |
| Hallucinations, olfactory (2) | |
| Hallucinations, visual (110) | |
| Headache (1065) | |
| Hoigne's syndrome (5) | |
| Horner's syndrome (1) | |
| Hostility (11) | |
| Hyperactivity (21) | |
| Hyperalgesia (16) | |
| Hyperesthesia (87) | |
| Hyperkinesia (2) | |
| Hypersexuality (6) | |
| Hypersomnia (12) | |
| Hyperthermia (18) | |
| Hypervigilance (1) | |
| Hypoesthesia (numbness) (78) | |
| Hypogeusia (5) | |
| Hypokinesia (11) | |
| Hypomania (13) | |
| Hyporeflexia (3) | |
| Hyposmia (4) | |
| Hyposomnia (2) | |
| Hypothermia (20) | |
