Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Extravasation is the accidental administration of intravenously (IV) infused medicinal drugs into the surrounding tissue, either by leakage (e.g., because of brittle veins in very elderly patients), or direct exposure (e.g. because the needle has punctured the vein and the infusion goes directly into the arm tissue). Extravasation of medicinal drugs during intravenous therapy is a side-effect that can and should be avoided. In mild cases, extravasation can cause pain, reddening, or irritation on the arm with the infusion needle. Severe damage may include tissue necrosis. In extreme cases, it even can lead to loss of an arm.