Informed Consent as a Shield and Sword: Legal Limits of Patient Autonomy

Informed consent in South African law is more than a procedural requirement — it is a constitutional and statutory safeguard that affirms the patient’s right to autonomy. It serves a dual legal function: protecting healthcare practitioners from liability when properly obtained, and empowering patients to challenge medical negligence when it is absent or flawed.

The legal foundation for informed consent is rooted in the Constitution, particularly section 12(2), which guarantees bodily and psychological integrity, and section 10, which affirms the right to dignity. The National Health Act 61 of 2003 reinforces this by requiring full disclosure of diagnosis, treatment options, risks, and consequences before any medical intervention. At common law, failure to obtain informed consent may constitute assault or negligence.

For consent to be valid, three elements must be present: disclosure of material risks and alternatives, comprehension by the patient, and voluntary agreement by someone with legal and mental capacity. Materiality is judged from the perspective of a reasonable patient — not the practitioner — and must include risks that could influence the patient’s decision.

When properly executed, informed consent acts as a shield for practitioners. If a patient was fully informed and voluntarily accepted the risks, the practitioner may not be held liable for adverse outcomes that were disclosed. This principle was affirmed in Castell v De Greef, where the court adopted the “reasonable patient” standard and recognised informed consent as essential to lawful medical treatment.

Conversely, informed consent can be used as a sword by patients. If material risks were not disclosed, or if consent was obtained under duress or misinformation, the patient may have grounds for a malpractice claim. Courts have recognised that informed consent is not a mere formality but a substantive right that must be respected.

However, patient autonomy has limits. In emergencies, consent may be implied if immediate treatment is necessary to preserve life. Public health legislation may override individual consent in cases involving communicable diseases or mental health interventions. Patients may also refuse treatment, but such refusal must be informed and properly documented.

Ultimately, informed consent is not just a signed form — it is a process of meaningful communication. Its legal power depends on clarity, context, and respect. When properly applied, it protects both the practitioner and the patient, reinforcing ethical medical practice and constitutional values.