IIEF-5 Questions Explained: What Each One Measures

The International Index of Erectile Function (IIEF-5) — also called the SHIM — is a deceptively nuanced instrument used to grade erectile dysfunction [2]. While its five questions appear straightforward, each is carefully worded to capture a specific aspect of erectile function. Understanding what each question is actually measuring helps you answer accurately and ensures your score reflects your true situation.

Question 1: Confidence

'How do you rate your confidence that you could get and keep an erection?' — This question assesses self-efficacy and psychological erectile function. It captures performance anxiety, which is the leading cause of ED in men under 40. A low score here with normal scores elsewhere suggests primarily psychological rather than vascular ED.

Question 2: Erection Hardness During Stimulation

'When you had erections with sexual stimulation, how often were your erections hard enough for penetration?' — This captures the rigidity phase of erectile function. It is the question most directly correlated with penile arterial inflow. Low scores on Q2 alongside low confidence (Q1) suggests mixed vascular-psychological origin.

Question 3: Erection Maintenance After Penetration

'During sexual intercourse, how often were you able to maintain your erection after you had penetrated your partner?' — This specifically assesses venous leak — the inability to maintain an erection after initial tumescence. Men with venous leak can achieve erections but cannot sustain them. This is a distinct mechanism from arterial insufficiency.

Question 4: Difficulty Maintaining to Completion

'During sexual intercourse, how difficult was it to maintain your erection to the completion of intercourse?' — Q4 assesses the functional duration of erectile rigidity during the full duration of intercourse. Low scores here combined with normal Q2 scores strongly suggest venous leak or pelvic floor weakness (bulbospongiosus muscle insufficiency).

Question 5: Overall Satisfaction

'When you attempted sexual intercourse, how often was it satisfactory for you?' — This is the only question that captures the subjective experience of sexual satisfaction rather than the mechanical process of erection. It integrates all previous components plus psychological factors. Men with adequate erections but premature ejaculation, for example, may score low on Q5 despite scoring normally on Q1–4.

Common Scoring Mistakes to Avoid

• •Answering 'no sexual activity' as 0: Questions Q2–5 that reference intercourse should be scored as 0 only if there was no attempt. If you avoided intercourse due to anticipated ED, this avoidance itself reflects the problem and should be scored honestly.
• •Scoring based on best-case rather than typical performance: The questions ask about usual experience — not your best night. Consistent overestimation leads to underdiagnosis.
• •Including solo stimulation: The IIEF-5 specifically measures partnered sexual activity. Non-partnered erections (morning erections, masturbation) are assessed separately in full IIEF-15 but are not part of the 5-item version.

Interpreting Your Total IIEF-5 Score

The IIEF-5 produces a total score between 5 (minimum, answering 1 on all questions) and 25 (maximum, answering 5 on all questions). Score ranges were validated against clinician-assessed ED severity in the original Rosen et al. 1999 paper. A score of 22–25 indicates no ED. A score of 17–21 indicates mild ED. A score of 12–16 indicates mild-to-moderate ED. A score of 8–11 indicates moderate ED. A score of 5–7 indicates severe ED. Men who have not attempted intercourse in the past six months can still complete the IIEF-5, but the intercourse questions then score zero, which lowers the total [2].

• •Score 22–25: No ED — monitor annually or if symptoms change
• •Score 17–21: Mild ED — lifestyle intervention first; discuss with GP if persistent beyond 3 months
• •Score 12–16: Mild-to-moderate ED — warrants medical evaluation; vascular risk factors should be assessed
• •Score 8–11: Moderate ED — medical evaluation indicated; PDE5 inhibitor trial appropriate
• •Score 5–7: Severe ED — comprehensive evaluation including hormonal, vascular, and neurological assessment
• •A drop of 5 or more points between assessments: clinically meaningful deterioration requiring prompt evaluation

Using the IIEF-5 to Diagnose the Type of ED

Beyond the total score, the pattern of responses across the five questions points toward different ED mechanisms. A man scoring low on Q1 (confidence) but relatively higher on Q2–4 likely has primarily psychogenic ED — where the erection mechanism is intact but activation is impaired by anxiety. A man scoring normally on Q1 but low on Q2 (hardness during stimulation) has vascular insufficiency as the likely cause — the arterial inflow is inadequate for adequate tumescence. A man scoring well on Q2 but poorly on Q3 and Q4 (maintenance) has venous leak as the likely mechanism — blood enters adequately but escapes too quickly. Understanding these patterns helps clinicians target treatment correctly rather than defaulting to PDE5 inhibitors for all presentations.

When the IIEF-5 Should Be Completed by a Partner

Research shows that men self-report higher IIEF-5 scores (indicating less ED) than their partners report on their behalf — suggesting men systematically underreport erectile difficulty when self-assessing. For men who feel uncertain about how to rate their experience, completing the questionnaire together with a partner produces more accurate results. This is not a substitute for the patient's own completion, but partner input can help calibrate answers, particularly on Q5 (satisfaction), where subjective assessment varies most widely between how men and partners perceive the same sexual encounter.

What Each IIEF-5 Question Actually Measures

• •Question 1 — Erection confidence: 'How confident are you that you could get and keep an erection?' Captures the psychological anticipation component and performance anxiety
• •Question 2 — Erection frequency: 'When you had erections with sexual stimulation, how often were your erections hard enough for penetration?' Reflects the reliability of the vascular response
• •Question 3 — Erection firmness: 'When you attempted sexual intercourse, how often were you able to penetrate your partner?' Directly measures erectile rigidity sufficient for intercourse
• •Question 4 — Erection maintenance: 'During sexual intercourse, how often were you able to maintain your erection after you had penetrated your partner?' Assesses veno-occlusive competence — the ability to trap blood in the corpora
• •Question 5 — Satisfaction: 'How difficult was it to maintain your erection to completion of intercourse?' Captures the overall experience and satisfaction outcome

IIEF-5 Scoring Thresholds

Each question is scored 1–5 (with 0 for no sexual activity). Total scores range from 5 to 25. The validated severity thresholds are: 22–25 = no erectile dysfunction; 17–21 = mild ED; 12–16 = mild-to-moderate ED; 8–11 = moderate ED; 5–7 = severe ED [2]. These thresholds were derived from the original IIEF validation study of over 1150 men and have been replicated across multiple international populations. A score of 21 or below warrants medical evaluation regardless of age.

How to Answer Accurately

The IIEF-5 asks about the past six months [2]. Answer based on your actual experiences, not your best or worst days — typical function is what's being assessed. Include sexual activity with or without a partner. If you had no sexual activity due to ED (not due to circumstance), answer accordingly rather than selecting 'no sexual activity' — the latter artificially raises scores and delays correct treatment. Underreporting on self-assessment tools is extremely common and directly delays accurate diagnosis.

IIEF-5 vs. the Full IIEF-15

The full International Index of Erectile Function (IIEF-15) contains 15 questions covering five domains: erectile function (Questions 1–5 and 15), intercourse satisfaction (6–8), orgasmic function (9–10), sexual desire (11–12), and overall satisfaction (13–14) [1]. The IIEF-15 is the gold standard used in clinical trials and pharmaceutical research. The IIEF-5 (also called the Sexual Health Inventory for Men, or SHIM) is a validated 5-item subset used in clinical practice for efficiency. Both tools are validated and clinically useful; the IIEF-5 is preferred for initial screening and monitoring in busy clinical settings.

Using the IIEF-5 to Monitor Treatment Response

Repeat the IIEF-5 at 4–8 week intervals after starting any new treatment. A minimum clinically important difference (MCID) of 4 points on the IIEF-5 is considered a meaningful response. If your score has not improved by at least 4 points after 8 weeks of PDE5 inhibitor therapy, the dose, timing, or diagnosis warrants reassessment. Plateau or decline after initial improvement suggests treatment resistance, secondary psychogenic overlay, or a new contributing condition.