slemvätskan

Slemvätskan, commonly referred to as mucus, is a viscous, water-rich secretion produced by goblet cells and mucous glands in the lining of mucous membranes throughout the body, especially in the respiratory and digestive tracts. Its primary roles are to lubricate surfaces, protect against drying, trap dust and pathogens, and contribute to the immune defense by transporting antimicrobial substances such as lysozyme, lactoferrin, and secretory IgA. The gel-like consistency is due to mucins, large glycoproteins, with MUC5AC and MUC5B being particularly important in the airways.

In healthy individuals, mucus is clear and easily cleared by the mucociliary escalator, a coordinated movement of cilia lining the airways. Its production and viscosity are influenced by hydration, inflammation, and infection. When hydration is adequate and there is no active inflammation, mucus remains at a level that facilitates normal clearance.

In disease, mucus production can become excessive or thicker, hindering clearance and contributing to symptoms such as coughing, congestion, and airway obstruction. Conditions that commonly involve altered mucus include allergic rhinitis, sinusitis, chronic bronchitis, asthma, chronic obstructive pulmonary disease, and cystic fibrosis. In these settings, mucus may be more viscous, purulent, or difficult to expectorate.

Management aims to support normal mucus clearance and reduce excessive production. Approaches include maintaining adequate hydration, humidification of the air, treating underlying inflammation or infection, smoking cessation, and, when appropriate, pharmacological therapies such as mucolytics or expectorants prescribed by healthcare professionals.