Overview
Coughing is a protective reflex that clears the airways of irritants, secretions, and foreign particles. This HealthKit category type allows users to track coughing episodes and their severity, providing valuable data for monitoring respiratory illness progression, identifying triggers, and assessing treatment effectiveness.
Health Significance
Cough is classified by duration:
- Acute cough: Less than 3 weeks (usually infectious)
- Subacute cough: 3-8 weeks (often post-infectious)
- Chronic cough: Greater than 8 weeks (requires investigation)
Common causes of acute cough:
- Upper respiratory tract infections (common cold)
- Influenza and COVID-19
- Acute bronchitis
- Pneumonia
- Pertussis (whooping cough)
Common causes of chronic cough:
- Postnasal drip / Upper airway cough syndrome
- Asthma and cough-variant asthma
- Gastroesophageal reflux disease (GERD)
- ACE inhibitor-induced cough
- Chronic bronchitis / COPD
- Bronchiectasis
Concerning causes:
- Lung cancer
- Tuberculosis
- Interstitial lung disease
- Heart failure
When to Seek Medical Attention
Users should seek medical evaluation when cough:
- Persists for more than 3 weeks
- Produces blood or bloody mucus (hemoptysis)
- Is accompanied by unexplained weight loss
- Is associated with fever lasting more than a week
- Causes shortness of breath or wheezing
- Disrupts sleep significantly
- Is accompanied by chest pain
- Occurs with night sweats
- Is progressively worsening
- Occurs in smokers or former smokers
- Is associated with voice changes
Pattern Recognition
Clinicians can use longitudinal data to identify:
- Illness progression and resolution
- Nocturnal patterns (GERD, asthma, postnasal drip)
- Seasonal patterns (allergies, asthma)
- Environmental triggers (occupational, pollution)
- Response to treatment (bronchodilators, acid suppression)
- Post-infectious cough duration
- Correlation with medication changes (ACE inhibitors)
Caveats & Limitations
- Does not capture cough characteristics (dry vs. productive)
- Sputum color and quantity not recorded
- Frequency of coughing episodes not quantified
- Cannot differentiate between cough triggers
- Associated symptoms (wheezing, dyspnea) not captured
- Time of day patterns require careful logging
- Does not replace pulmonary function testing
Related Metrics
HKCategoryTypeIdentifierShortnessOfBreath
Respiratory conditions often cause both cough and dyspnea
HKCategoryTypeIdentifierFever
Fever with cough suggests infection
HKCategoryTypeIdentifierChills
Chills with cough indicate infectious etiology
HKCategoryTypeIdentifierSoreThroat
Upper respiratory infections cause both symptoms
HKCategoryTypeIdentifierRunnyNose
Postnasal drip is a common cause of chronic cough