dissenting:

We review the district court’s judgment de novo to determine whether the administrative law judge’s (ALJ’s) decision is supported by substantial evidence in the record as a whole and applies the correct legal standards. Osenbrock v. Apfel, 240 F.3d 1157, 1162 (9th Cir.2001). Substantial evidence is such relevant evidence that a reasonable mind might accept as adequate to support a conclusion. Id. The ALJ’s findings must be upheld if they are supported by inferences reasonably drawn from the record. Id. If evidence exists to support more than one rational interpretation, this court must defer to the ALJ’s decision. Id. Because a thorough review of Mickey Webb’s medical records shows that there is substantial evidence to support the ALJ’s determination that Webb did not suffer from a severe impairment during the relevant period, I respectfully dissent.

I.

In June 1987 Webb was involved in an ATV accident that resulted in multiple rib fractures and possible facial injures. X-rays of the thoracic and cervical spines taken at the time were “essentially unremarkable.” There is no evidence of further medical treatment, to such spines or otherwise, until August 1989 when Webb sought emergency room treatment for weakness and numbness in his left arm. Webb reported that he had felt weak for a number of years. The examining physician determined that the symptoms were caused either by stress or hypertension and recommended that Webb eat breakfast and lunch (which he had not done that day). Webb continued to maintain steady employment following the ATV injury until 1991. 1

In October 1991, Webb reported visual disturbance and memory loss. A CT scan of the brain revealed “no evidence of hypertensive bleed or other intraparenchymal[organ tissue] abnormalities.”

On April 9, 1992, Webb reported to Dr. Donnelly that he had been doing quite well and had no problems with headaches or visual discomfort or transient ischemic attack symptoms 2 since his blood pressure had been under control. Dr. Donnelly noted, “evidently he quit his job as he was just kind of ‘puttering around.’ ” Webb’s hypertension was also “under good control.”

On December 7, 1993, Webb sought medical treatment after a foreign body hit his right eye while he was working with a table saw. 3 In October 1994, Webb was treated for lower back pain. It was noted that Webb had discontinued his hypertension medication in April 1992 due to fatigue, but had not gone to see a doctor since then. Dr. Naymik noted that Webb’s hypertension was “poorly controlled” and prescribed Dilacor (hypertension medication) and Relafen (pain medication). A chest x-ray was within normal limits with poor resolution of the thoracic vertebrae, and an electrocardiogram (EKG) was also normal.

On November 7, 1994, Webb reported that he was feeling better with regard to *690 his upper extremity pain, neck pain, and blood pressure, and now wanted to “deal with his low back pain.” Webb traced his back problems to a 1983 work injury, rather than the 1987 ATV accident, but explained that he had not sought care since that time despite recurrent episodes of back pain. Webb explained that his back “[gave] way” sometimes if he stood in one place and he occasionally fell down.

The “clinical sheet” prepared by Dr. Naymik notes that Webb’s blood pressure was “much improved” and that Webb was to continue taking Relafen and Dilacor daily. Webb’s left shoulder, arm and mid-thoracic back pain symptoms had improved with anti-inflammatory medications. Dr. Naymik further noted that Webb’s “[b]ack is straight to palpation. Deep tendon reflexes are symmetrical. Straight leg raising is negative. Upper extremity left arm deep tendon reflexes are good.” An x-ray of the lower back “demonstrated disc space narrowing at L4-L5” and Dr. Naymik suspected degenerative disease. Dr. Naymik advised Webb to “continue to protect his lower back and to do appropriate low back exercises.” He also suggested Webb consider an MRI scan and/or neurosurgical evaluation to check for “disc fragmentation or significant herniation at the L4-L5 level” but Webb said he needed to think it over.

On February 3, 1995, Webb reported injuring his left hip during the previous week while helping a friend build garage doors. Webb reported that he had experienced similar pain “3 to 6 months ago after getting in and out of small cars.” He described his general health as “good” and noted that he continued to take blood pressure medication without side effects. It was further noted that he remained unemployed and spent his days working around the house. Webb reported that he exercised by walking five miles twice a week.

In April 1996, Webb was treated for a blistered right hand, possibly related to weeding, or mechanical work involved in installing brakes on his car. In May 1996, Webb presented with complaints of left knee pain and swelling that had lasted about a week. Webb had fluid in his knee, but an x-ray revealed only “minimal degenerative changes.” 4 A medical report from the next month noted that the knee was “quite a bit better.”

On July 8, 1996, Webb complained of back pain when he lied down, and reported that he napped daily. Webb’s blood pressure was elevated and Dr. Naymik switched him to a new hypertension medication (Norvasc). Physician’s notes from July 17, 1996 indicated that Webb was taking his medication without side effects and it “seemfed] to be lowering his B/P [blood pressure] adequately.” On September 26, 1996, Webb reported continuing back pain, and requested more Relafen, a pain medication which “worked for him.”

In November 1996, Webb was briefly treated for an episode of intestinal problems. Dr. Naymik assessed him with possible diverticulitis (inflammation of the colon), which was getting better, or gastroenteritis (inflammation of the stomach or intestines), and prescribed antibiotics.

There is no evidence of medical treatment during 1997. Webb’s insured status expired on September 30, 1997. Therefore, the relevant period for his disability status is only that which predates September 30, 1997. See 20 C.F.R. §§ 404.981 , 422.210.

In 2000, Webb filed an application for disability insurance benefits, alleging disability since 1991 due to back pain, high blood pressure, arm pain, weakness and *691 lack of sleep. After his application was denied initially, and upon reconsideration, Webb applied for a hearing before an ALJ. The ALJ determined that Webb was not disabled because he did not suffer from a severe impairment during the relevant period.

II.

In assessing the severity of Webb’s alleged impairments, the ALJ properly considered the medical evidence and noted, “[T]reating records from his 1991 alleged onset date through his 1997 date last insured are relatively sparse, and depict a pattern of only transitory and intermittent medical conditions rather than any chronic condition which would produce significant work-related restrictions.” Substantial evidence supports the ALJ’s assessment. 5

As noted above, Webb’s October 1994 chest x-ray was within normal limits with poor resolution of the thoracic vertebrae. An electro-cardiogram (“E.K.G.”) performed at the same time was also normal. In May 1996, Webb sought treatment for fluid in his knee, but an x-ray revealed only “minimal degenerative changes,” and a medical report from the next month noted that the knee was “quite a bit better.” A lumbar x-ray taken in July 1996 was unremarkable, and Webb’s doctor reported that Webb’s symptoms were controlled with medication. Physician’s notes from July 17, 1996 indicated that Webb was taking his medication without side effects and that the medication seemed to be lowering his blood pressure adequately. 6 On *692 September 26,1996, Webb requested more Relafen, a pain medication which “worked for him.” There is no evidence of medical treatment during 1997 and Webb’s insured status expired on September 30,1997.

As the ALJ also noted, Webb’s activities during the relevant period, as reported in his medical records, including working with a table saw, doing normal household chores, and walking five miles twice a week, were not consistent with a severe disability. Id. See 20 C.F.R. § 404.1521 (a) (“An impairment or combination of impairments is not severe if it does not significantly limit [the] physical or mental ability to do basic work activities.”); 20 C.F.R. § 404.1521 (b) (defining “basic work activities” as the “abilities and aptitudes necessary to do most jobs” including physical functions such as walking, standing, sitting, lifting, pushing, pulling, reaching, carrying, or handling).

Because the ALJ’s determination that Webb did not suffer from a severe impairment at step-two of the five-step sequential analysis was supported by substantial evidence I would affirm the ALJ’s finding that Webb is not disabled within the meaning of the Social Security Act.

. Webb's alleged onset date of disability is August 1, 1991, when he stopped working.

. A brief episode of cerebral ischemia (deficient supply of blood to the brain) that is usually characterized by temporary blurring of vision, slurring of speech, numbness, or paralysis.

.A small metallic foreign object was removed and he was discharged “in good condition.” Webb does not allege any change in his vision resulting from this injury.

. Webb was age 44 at this point.

. The majority attempts to excuse Webb’s failure to provide sufficient evidence of a severe disability by asserting that "[t]he ALJ had an affirmative duty to supplement Webb's medical record, to the extent it was incomplete, before rejecting Webb's petition at so early a stage in the analysis.” Majority Op. 687. As the majority recognizes, however, although an ALJ "has an independent duty to fully and fairly develop the record,” Smolen, 80 F.3d at 1288, this duty is triggered by ambiguous evidence, or the ALJ's own finding that the record is inadequate to allow for proper evaluation of the evidence. Tonapetyan v. Halter, 242 F.3d 1144, 1150 . Neither was the case here. Here, the sporadic nature of Webb’s medical records supports the ALJ’s determination that Webb’s impairments were not severe. During the administrative process, Webb never asserted that his medical records were incomplete and, as the majority recognizes, Webb ultimately bore the burden of establishing disability, and had a duty to provide evidence of such disability. Bowen, 482 U.S. at 146, 107 S.Ct. 2287 .

. The majority states: “During the next several years, Webb continued to suffer from lower back pain and hypertension. He went on and off a variety of medications. Although some had positive results, their side effects were often intolerable. Because of his ailments and the side effects of their treatment, Webb stopped working.” Majority Op. 16783. During his testimony before the ALJ, Webb stated that when his blood pressure is lowered to a normal level (by medication) he feels "sluggish,” "weak and sleepy.” Webb explained that he tried about 20 different medications over the years but when his "pressure would get down to where it belongs — which is basically 120/80 — when I'm at that level, I can’t operate and I hurt and ache. I can operate at 140-150 over 95 or so. That's where I try to operate at this day. I can handle it. That’s too high, but I can at least function. Or my pain pills, they ruin my blood pressure so I try to monitor it accordingly. [Q: Okay. So you feel better when your blood pressure is high] A: Yes.”

As explained above, Webb’s medical records provide substantial evidence to support the ALJ's determination that the side effects of Webb’s medication did not constitute a severe impairment, much less were they intolerable. In summary, On October 27, 1994 Dr. Naymik prescribed Dilacor (hypertension medication) and Relafen (pain medication). On November 7, 1994, Dr. Naymik noted that Webb’s blood pressure and upper extremity pain was "much improved” and instructed Webb to continue taking his medication daily. On February 3, 1995, Webb reported that he continued to take his blood prfessure medication without side effects and described his general health as "good.” On July 8, 1996, *692 Dr. Naymik switched Webb to a new hypertension medication (Norvasc), and physician’s notes from July 17, 1996 indicate that Webb was taking his medication without side effects and it "seem[ed] to be lowering his B/P [blood pressure] adequately.”