Why Can't I Get a Full Erection? List of Potential Causes

Failure to achieve a full erection is a common problem that both older men and younger men in the United States experience. In fact, some research indicates that 30 million American men experience symptoms of erectile dysfunction — and it’s not always clear why.

The causes of erectile function problems can be any number of things. Alcohol may cause temporary ED and medications may cause erectile problems. Health conditions like kidney disease, obesity, vascular health issues and medical conditions of the nervous system may all affect a man’s ability to maintain an erection. It might even be an issue that comes as a symptom of a mental health condition.

If you’re asking questions like “Why couldn’t I get hard the last time I had sex” or “Why can I only get a semi hard on” then the answers list could help you get a sense of where the issue might be.

Why Do Some Guys Get Harder than Others?

Erections are about two things: blood flow in, and no blood flow out. Your penis is essentially a balloon filled with blood. Actually, there are two main ones in the penis, and together they’re called the corpora cavernosa (there’s also a third, softer one called the corpus spongiosum).

When you become aroused, these “balloons” fill with blood, and the increased pressure pushing against the surrounding fibrous tissue seals off the exit, trapping that blood inside your penis. Erections fail to happen only when something interrupts this process, and there are a few things that can do that. 

Some of these things include: 

  • Weight

  • Age

  • General health 

  • Alcohol consumption

  • Drug dependency

  • Medication side effects

Those are just a few on a long list of physical and mental causes (which we’ve elaborated on below).

Physiological or psychological factors may impair a man’s ability to get hard, and they may also experience partial erections due to these factors.

FYI: partial erections are health issues, as well as warning signs for erectile dysfunction. While they’re not as severe as a complete lack of firmness, they represent a problem that needs to be tackled before it gets worse. 

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Why Can’t I Get Fully Hard?

A variety of causes and mental health triggers might cause any man to experience sexual health issues. 

If you’ve experienced (or might currently be experiencing) any of the following conditions, issues or problems, you’re at risk for ED. 

Below, we’ve organized them into two primary categories: physiological reasons like those associated with heart health, and psychological reasons like those related to performance anxiety or depression.

Physiological Reasons

Your erectile health is not independent from the health of the rest of your body, so if something is going wrong in another area of the factory, so to speak, it could still shut down the production line elsewhere.

One form of ED — arteriogenic ED — is caused by inefficient arteries which are associated with heart disease. 

Common examples of conditions that can increase your risk of ED include:

  • Chronic inflammation associated with diabetes 

  • High blood pressure

  • Metabolic syndrome

  • Cardiovascular and neurological diseases

  • Multiple sclerosis (MS) 

  • Parkinson’s disease

There are even neurological causes of erectile dysfunction to consider, like nerve damage or similar traumas that reduce sensation and function in the penis. 

Things like hormonal imbalances (which can be caused by age, weight or any number of factors) can throw off your libido.

It’s important not to rule out things like lifestyle choices and habits as potential causes of ED, too. The underlying cause of ED could be anything from poor diet and exercise habits to unknown medication side effects. 

If you’re experiencing partial erections or are unable to maintain a full erection, you’re possibly suffering from one or more of these conditions. And if you suspect any of these health conditions may be holding you back in the bedroom, talk to a healthcare professional.

Psychological Reasons

Even if your body may be causing some problems for your erectile health, your mental health could be affecting things simultaneously. Gained some weight recently? It might be affecting your heart health, but it might also be making you self conscious in intimate scenarios.

Meanwhile, performance anxiety, depression and low self-esteem can adversely affect your ability to get hard by distracting you from arousing thoughts or lowering your interest in sex.

Stress and anxiety might cause a loss of interest in sexual activity generally, so if things in the office or the relationship aren’t great, the problems may be following you all the way to bed. 

Some believe that pornography can also cause a form of ED, and while the jury is still out on that one, considering whether your porn habit feels like part of the problem has apparently led some men to see benefits from cutting back.

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What to Do If You Can’t Get a Full Erection 

There's a very wide spectrum of severity that can affect different men to different degrees — your medications, underlying health issues, age and other factors may weigh on your erectile firmness, so it’s best to ask a professional to assess these possible ED causes.

Your healthcare provider will check you out for things like: 

  • Blood pressure issues

  • High cholesterol 

  • Side effects or interactions of medications (particularly, medications for hypertension and antidepressants)

  • Low testosterone levels

  • Prostate cancer

They may also inquire about not-so-physiological things like relationship problems and habits like your smoking, drug, alcohol and eating habits — those are ED causes you can address yourself or with help.

They’ll be able to help you figure out the right treatment for you. In many cases, they’ll suggest one or more of the following:

  • Lifestyle-Based Treatments

  • Medications

  • Therapy

Lifestyle-Based Treatments

When we discuss treatment options for sexual dysfunction, there’s one straightforward solution to ED that you should know about first: take better care of yourself. 

Before you run to the pharmacy, understand that ED is very treatable, with a variety of proven options available. Everything from diet and exercise, to medications and healthy lifestyle changes, can help you regain firmness. 


Your healthcare provider may also prescribe FDA-approved erectile dysfunction medications. There are currently four oral prescription ED pills available:

These drugs belong to a class of medications called phosphodiesterase type 5 inhibitors (PDE5 inhibitors for short) and work to increase blood flow to the penis to help you get and maintain an erection when you want one.

There are also other medications available for ED, such as alprostadil — an injectable medication.


A word of advice: don’t assume the cause is physical. Low self-esteem, performance anxiety and a slew of other mental health disorders can cause ED, and those should be treated with the help of a therapy professional. 

There are various psychological treatments and approaches to dealing with the ED problem. 

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Getting The Full Erection: Next Steps

“I can’t get rock hard anymore.” It’s a tough thing to admit, to type into a search bar or to say out loud to a healthcare professional. At least it feels that way. 

In reality, admitting the problem is a necessary first step to, well, being able to have a full erection again. 

If you haven’t been achieving full liftoff recently, remember these key facts:

  • It’s a whole-body issue. Erections are about more than your penis. Your whole body and your mind also contribute to the health of your erections.

  • Your mind may be holding you back. Your body can be ready, but if you’re anxious, depressed or self-conscious, you may be left semi-erect.

  • This is a fixable problem. Like an electric crew doing pole work, medication and healthier living can restore your penile power, as can talking to a therapy professional if your erection problems are in your head.

Here’s the best part: we can help. 

We offer a variety of solutions, from some of the very ED medications we’ve mentioned to mental health support.

This article is for informational purposes only and does not constitute medical advice. The information contained herein is not a substitute for and should never be relied upon for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment or medication.

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