ICD-10 (International Classification of Diseases, 10th Revision) is a system used by healthcare providers to classify and code all diagnoses, symptoms and procedures. Key points:

• ICD-10 codes are alphanumeric and can be up to 7 characters long
• The first character is always alphabetic, representing the category
• Characters 2 and 3 represent the related group of diseases
• Characters 4-6 provide more specific information about the diagnosis
• The 7th character is an extension used in injury codes

This tool provides a basic lookup functionality. For comprehensive and up-to-date information, always refer to official ICD-10 resources.