Is Oleander Poisonous?

Toxicity. 

Oleander (Nerium oleander) is highly toxic, with all parts of the plant—including leaves, flowers, stems, and sap—containing potent cardiac glycosides like oleandrin and neriin. Ingestion can lead to severe health effects, including:Gastrointestinal Symptoms: Nausea, vomiting, abdominal pain, and diarrhea are common and can occur within hours of ingestion. 

Cardiac EffectsSymptom. 

Oleander poisoning can cause bradycardia (slow heart rate), irregular heartbeat, and even heart block or ventricular dysrhythmias, potentially leading to fatal outcomes.

Neurological Symptoms.

Confusion, dizziness, visual disturbances (such as halos), and lethargy may also manifest. Even skin contact with oleander sap can cause irritation. The plant's toxicity is serious enough that even small amounts can result in significant health risks, making it crucial to handle it with care.