Is phantom limb pain biological or psychological?

both
The brain will still send signals intended for nerve endings that no longer exist.
how the brain interprets the sign it gets back could give pain or an itch

psychological is harder - your unconscious and conscious brain are dealing or conflicting,
You can see the limb is missing but try telling your brain that

I would believe that would be psychological.

I believe it is biological.

psychological.

psychological. I know a guy that takes placebo pills to "relieve" the pain

My father suffered from limb pain. It was so bad he asked them to cut his leg off but they didn't he remained in pain.

BOTH : Even when a limb is amputated, damage to nerve endings is one thing that creates this sensation. subsequent regrowth can lead to abnormal and painful discharge of neurons in the stump, and may change the way that nerves from the amputated limb connect to neurons within the spinal cord. There is also evidence for altered nervous activity within the brain as a result of the loss of sensory input from the amputated limb.

Unfortunately, phantom limb pain is chronic; once it develops it persists and is rarely improved by present medical treatments. Destructive surgical procedures are also of limited use. They can be effective for a few months, but pain always returns, frequently worse, and so surgery is only performed in patients with terminal illness

Phantom limb pain is pyschological.

Well i think its psychological as i am an amputee,not only do i get phantom pains but if i do not think about my amputation it still feels like my leg is still there,I get itchy feet,If my left foot gets cold it feels like both of my feet are cold.

Pain is, these days, considered to be made up of both physiological and psychological components.

Experiments in recent years, using mirrors to make the remaining limb appear to be the amputated one, whilst carrying out movements, reduced pain levels in the people studied. This suggests that, as well losing sensory input from the missing limb, loss of motor control (i.e. being able to move it) plays a part. It is thought that it is the mis-match between nerve signals to and from the missing limb and the brain's map of the body that is interpreted by the brain as pain. This is a physiological explanation, however there may be psychological factors too, as in any type of chronic pain.

DOC: in my view, the nervous system is physiological, i.e. part of our body; I agree with you that it is one complex part of it!

It is neither, it's actually neurological, even if you have a limb amputated the brain because of it's make up will stll be sending messages to and from the area, it is easy to fool the brain, the nervous system is extremely complex, and is split into two, the Autonomic and peripheral, and the pathways and functions are infinite!