I. Allergy and Pollen -- 1. What Is Allergy? -- 2. The Overview of Allergic Immune Mechanism -- 3. Who Has Allergic? -- 4 What Is Aeroallergen? -- 5. Pollen As Aeroallergen -- 6. Evaluation of Pollen Allergy -- 7. Factors Influencing Clinical Significance of Pollen -- II. The Formation of Pollen -- 1. The Production of Pollen -- 2. Pollination -- 3. Characteristics of Wind-Pollinated Plants -- 4. Allergens of Pollen -- III. Pollen Collection and Counting -- 1. Purpose of Standardized Air Sampling -- 2. Samplers -- 3. Operation -- 4. Pollen Identification -- 5. The Importance of Pollen Counting -- IV. The Structure of Pollen -- 1 Single Grains (Monads) Without Apertures -- 2. Monocolpate Grains (Monads) -- 3. Single Grain with Apertures -- V. Description and Clinical Exposure of Allergic Plants -- 1. Anatomy of Plant -- 2. Taxonomy -- 3. Description and Clinical Relation of Allergic Plants -- VI. Pollen and Climate -- 1. Effects of Weather on Allergen Load and Pollen Potency -- 2. Pollen Calendars -- 3. Effects of Weather on Pollen Flight -- 4. Forecasting Pollen Concentration -- 5. The Influence of Climate Change to Allergenic Pollen -- 6. Thunderstorm-Related Asthma -- VII. Pollen Allergy -- 1. Sensitization to Pollen -- 2. Pollen Threshold Levels for Symptom Development -- 3. Allergenic Pollen Species and Their Threshold Levels -- 4. Clinical Manifestation of Pollen Allergy -- 5. Diagnosis of Pollen Allergy.