Table 1.
Trigger categories and component terms.
| Trigger category | Verbatim trigger terms (n = number of studies using exact term) | Studies assessing each category |
|---|---|---|
| Activity/exertion | Activity (2), arms over head (1), banging head (1), bending over (1), chewing (1), cough (2), coughing (1), dancing (1), defecation (1), diving (1), evacuation (1), excessive work (1), exercise (4), exertion (3), exhaustion (1), head motion (1), head/neck movements (2), lack of exercise (1), lifting of weight (1), lifting overhead (1), loud speaking (1), military related (combat, wearing headgear or helmet, wearing MOPP gear, riding in a vehicle, firing a weapon, and flying in an aircraft) (1), moving neck (1), muscle tension/posture (1), neck movement (1), neck position (1), physical (1), physical (physical exertion and strenuous activity) (1), physical activity (5), physical effort (2), physical exercise (1), physical exertion (2), physical exhaustion or traveling (1), physical inactivity (1), physical strain or exercise (18), posture (2), racket sports (1), running/cardio (1), sexual activity (12), sexual intercourse (1), singing (1), squatting (1), straining (2), strenuous physical activity (1), tension in neck muscles (1), yoga (1) | 46 |
| Alcohol | Alcohol (32), alcohol (white wine) (4), alcoholic drinks (red wine, white wine, sparkling wine, beer, etc.) (5), all alcohol (1), all alcohol (red wine, white wine, clear spirits) (1), beer (5), beer spirits (1), hard liquor (1), red wine (6), red wine (but not white wine or clear spirits) (1), red wine/cheese (1), sparkling wine (1), spirits (4), tequila only (of alcohol) (1), too much of any alcohol (2), wine (3), wine, beer, other alcohol (1) | 43 |
| Allergy/sinus | Allergies (5), pollen (1), pollution (2), season of year (1), seasonal variation (1), sneezing (1), sniffing (1) | 7 |
| Auditory | Acoustic (1), loud noise (1), noise (14), noise (environmental) (2), noise (loud speakers, loud music) (1), too loud music (1) | 19 |
| Emotion | Acute emotion (1), afferent stimulation (1), aggressiveness (2), anger or hot temper (3), annoyance (1), anxiety (1), argument (3), behavioral (being scolded) (1), behavioral (shouting) (1), changes in mood (1), crying (4), distress (1), emotion (2), emotion (violent) (1), emotional (fear, anger, or other) (1), emotional changes (2e (1), fear (1), feeling sad (1), intense emotional influences (3), irritation (1), low mood (1), negative affect (anxiety, anger, depression) (3), thinking about negative events (1), worries (1) | 26 |
| Food/Eating Habits | After eating (1), aspartame (3), binge eating (1), break from coffee (1), cabbages (1), caffeinated drinks (2), caffeine (5), carbohydrates (1), certain food (5), cheese (7), cheese (including yogurt) (2), Chinese food (1), chocolate (7), chocolate (including cakes) (4), chocolate/milk/groundnut (1), citric fruits (3), coffee (5), consumption related (fasting, certain foods, certain beverages, dehydration, and caffeine withdrawal) (1), dark chocolate (1), dehydration (3), diet (1), dietary (2), drinking pop (2), eating habits (1), eggs (1), fasting (5), fatty food (1), fish (1), food (17), food additives (2), food seasonings (1), fried foods (2), fruits and vegetables (1), full meals (1), honey mead (1), hot dogs (1), hunger (18), hunger (missing a meal) (1), ice cream (3), khat (Ethiopian leaf) (1), meat (1), milk (2), milk/cheese (1), missing meals (3), monosodium glutamate (2), MSG (2), not eating (2), not eating on time (1), nuts (2), other dietary (1), other sugar containing foodstuffs (1), others (foods) (1), pizza (1), religious fasting (1), salami (2), sausage (2), skipping meals (6), soft drinks (2), some kinds of food (2), specific foods/drinks (1), sweets (1), too few beverages (1), tropical fruit (1), unhealthy diet (1), water deprivation (2) | 53 |
| Hormones | After menstrual period (1), hormonal changes (1), hormonal replacement (1), hormone (4), menopause (2), menses (2), menstruation (30), menstruation or break from pill (1), oral contraceptives (6), ovulation (2), perimenstrually (1), pre menstrual period (1), pregnancy (3) | 38 |
| Medications | Drug intake (1), medication (3), some drugs (1) | 5 |
| Other | Associated disease (1), bathing (1), boredom (1), cervical problems (1), chance (1), change of rhythm (1), destiny (1), diverse (1), genetic predisposition (1), hair wash alone (2), hair wash and other (1), hair wash concurrent with others (1), head injury (3), head trauma (3), headgear (1), hot shower (1), infections (2), infectious disease (1), massage (1), muscle pain (1), neck pain (4), nitroglycerin (1), no fresh air (1), other (1), others (perfumes, head trauma, GI upset) (1), pain in other body parts (1), postanesthesia (1), prevalent diseases (1), problems with braces (1), reading or general thinking (3), reflux (1), sensorial stimuli (1), sickness (2), smoking/illegal drug use (1), tobacco (1), using a low pillow (1), Valsalva maneuver (1), various discomforts (1), wearing a hat (1), weekends (2), wet cold hair (1) | 25 |
| Sleep | Change in sleeping habits (3), changes in time of sleep (3), fatigue (15), fatigue related (fatigue, exhaustion, and sleep deprivation) (1), few hours sleep (1), insomnia (1), insufficient sleep (1), lack of sleep (11), napping (2), nocturnal sleeping (1), oversleep (5), poor sleep (1), prolonged sleep (1), sleep (5), sleep (weekends) (2), sleep deprivation (9), sleep disturbance (10), sleep pattern change (1), sleep problems (1), sleeping late (3), sleeplessness (2), tired (1), tiredness (2), too much sleep (7), too much/too little sleep (2), undersleeping (1) | 53 |
| Smell/odor | Chemical smells (1) cigarette smoke (7), fumes/heavy scents (1), gasoline (2), household cleaners (bleach or chemicals) (1), odor or foul smell (5), odors (2), odors (perfumes, smoke) (1), odour specific (candles with scent) (1), odour specific (car exhaust/exhaust fumes) (1), odour specific (cigarette smoke) (1), odour specific (coffee) (1), odour specific (detergent) (1), odour specific (flowers with strong scent) (1), odour specific (fried food) (1), odour specific (garlic) (1), odour specific (grilled food) (1), odour specific (horse) (1), odour specific (incense) (1), odour specific (mould) (1), odour specific (perfume) (2), odour specific (petrol) (1), odour specific (pineapple) (1), odour specific (sesame seed) (1), odour specific (shower gel) (1), odour specific (smoke) (1), odour specific (sweat and bad breath) (1), odour specific (vanilla) (1), olfactory (1), perfume odour (9), perfumes or colognes (1), smell (7), smell (cleanness product) (2), smell (fat) (2), smell (food) (2), smell (odour) (3), smoke (5), smoke (auto emission) (1), smoke (smoking cigarettes) (3), smoking or smell of smoking (8), strong odours (2) | 41 |
| Stress | Academic stress (1), acute stress (1), acute stress (during stress) (2), acute stress (following stress) (1), after stress is over (2), cessation of stress (1), conflict (3), conflict (another person) (1), during stress (1), emotional stress (2), feeling worried (1), mental stress (3), personal problems (1), poor lifestyle (1), post crisis letdown (1), problems with friends (1), problems with parents (1), problems with teachers (1), prolonged concentration (1), psychological (3), relaxation (3), relaxation after stress (2), stress (31), stress (affective) (1), stress (extracurricular activity related) (1), stress (mental effort) (1), stress (unspecified) (1), stress and mental tension (1), stress (anxiety) (3), stress at home (2), stress at work (1), stress related (1), stress unrelated to work (1), stress with family (1), stresses (bereavement) (1), stresses (family stress) (2), stresses (school stress) (2), stressful feeling (1), tension (1), too much schoolwork (1), tragic event (1), work related stress (1) | 57 |
| Travel | Altitude (1), car/bus journeys (other than school) (1), commuting (bus or car) (1), driving (3), flying/high altitude (1), frequent traveling (1), height (1), journey (1), long distance travel (1), travel (2), travel in airplane (1), travel in train/plane (1), trip (1), vacation (1) | 17 |
| Visual | Alternate light and shade (1), bright flashing light (1), bright light (8), colors (1), computer related (1), contrasting patterns (1), excessive light (1), exposure to sun (3), eye strain (1), eyesight problems (3), flashing/flickering light (1), flicker (1), fluorescent light (3), glare (4), hours in front PC/TV/video games (2), intense light (2), light/sun (1), lights (9), orange colors (1), other visual stimuli (3), prolonged computer use (1), road stripes or cones (1), sun clarity (1), sun exposure (1), sunlight (11), sunlight/bright light (2), too many hours reading (1), VDU screens/computer (1), video games (1), visual disturbance (flicker, glare, eyestrain) (1), visual disturbance and negative affect (1), visual effort (1), visual stimuli (bright light (other than sun)) (1), visual stimuli (recreation reading) (1), visual stimuli (school book reading) (1), visual stimuli (TV watching) (2), watching TV (1) | 47 |
| Weather/environment | Air condition of work (1), air conditioning of car (1), air conditioning of home (2), barometric pressure changes (1), barometric drops (1), change of environmental temperature (1), climatic (1), cold air conditioner (1), cold environment (1), cold weather (7), cold wind (2), crowded place (1), environmental (2), environmental (noise, light, sun, heat, cold, fumes, odor, smoke, and vibration) (1), environmental factors (1), environmental heat (1), heat (9), heat/cold/weather (1), hot and humid climate (1), hot weather (5), other weather variable (1), overheated (1), poor ventilation (1), rain (3), season of year (1), seasonal variation (2), suffocating atmosphere (1), summer heat (1), temperature (1), thermal (1), warm climate (1), weather (11), weather change (22), wind (6), wind draught (1) | 53 |